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1/2021 | E
Powered by
• Know-how • Inside Rutronik
• Application • System Technology
• Automotive • Latest Components
Editorial
Editorial Alled herefro
Portolionse
K
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Andreas et aspitatibus aut fugitem fugitatidf vel
Mangler,
Director StrategicEt
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bus et veribus, ese eiciis adionsequi conse-
runt, tempos moloritas autat di sitis non coreptis est
Between “America First”
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and “Made in China 2025”
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quis as ab int event litae dolupta ssimint veligendi
Dear Readers, omnisque necus autenemqui ommodias aut et ut
quam que qui dolest officiis rem et in conet pla dolo-
While one part re
of officaerorum
the world hasraalready sit lam,got sapiet et autatem
its economy backconsequi
up and running again,
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the rest continue quas aut
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and forth aut pligend
between lockdown estias
and loosening re-
strictions. Thisrehasn’t
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electronics industry. We are experi-
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encing
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both the Consumer excea and Industrial
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segments, something thatexevenexplab
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major automotive giants are not being spared.
The massive winding-down of production in the second quarter of 2020 caused
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the supply chain that et are
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being felt acimus
today.
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But even if COVID-19 had not been te aeaqui
thing,autaspisint
the increasinges etpace
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for semiconductors. cus,while
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major American Et autem quat.
companies, China aims to close the gap as
quickly as possible with its “Made in China 2025” program. Even if it looks un-
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by China.
officte maxim eosto ipsundi tations equatur sim hit
And what aboutvolupta
Europe? tiptat.
It “spent years blissfully asleep at the wheel,” as Rutronik
CMO Markus Krieg put it in his interview (page 14), with its share of global elec-
tronic demand Nihilignit
dropping to quiaround
comnisit 8 percent—which
et rero dolorepedis basically
acimus
covers Apple’s or
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ibeatiinrerum
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this means for laborei
the relevance of European
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facturers prioritize supply. That
asi aditatem cum intsaid,
desthe Europeancus,
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eaquid to have heard the
alarm bells ringing, and for itsEt
qui doldfuptae. part is now
autem putting around 150 billion euros on the
quat.
table to secure local semiconductor production.
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and hopefully
ratqui rem in time
fuga.to secure
Beriti ditaEurope’s
et ped quofuture as a center
of innovation. beri
The restiis
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amenisinetthe fuga.
EUItatiis-
and in particular in
Germany needtiis reliable
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local partners
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competitive,
aboriaandnisneed to be able
to produce the quam
productsvenithey develop
doluptas exerowithout
eum having to spend
doluptatiam months waiting for
sundunt
allocations of the components
officte maxim eosto they ipsundi
need. Especially in thissim
tations equatur light,
hit there is benefit
to be found involupta
collaborations
tiptat. between these European businesses and European
distributors that are geared not just towards short-term gains but also the strategic
importance of the
Ebishome
iscimus market.
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n aliberu ptasimus perecusciat unt deliqui dissit fac-
As the third-largest distributoretur
est doluptiant in Europe,
molor sit, Rutronik
corem etcontributes
inveles es its
sin-expertise to sup-
port the programs
venisofexpellam,
the German government
qui vendae consed and the EU,
quam, because as a German
voluptat.it,
company, we care deeply volupta
culliquam about the sitfuture
lat fugiaof our
cus home
event. industries and of European
industry. Being active globally and ensuring the independence of local businesses
are not mutuallyNimusap
exclusive—quite
errore cum the hitatatuItae.
opposite. FairMagaliberu
competitionptasi-for the best innova-
tions and the most
musefficient
perecusciat technologies
unt deliqui is ultimately
andam sa beneficial
cus, cor alici
to us all.
vellant lignis eic te senditaest quam fugiaspis restias
Sincerely, aut parum exerum harum adis voles dolorem volupta
Andreas Mangler
XXX@markt-technik.de
www.rutronik.com Committed to Excellence 3 3
Contents
Editorial 3 Automotive
Automotive MOSFETs:
• Know-how
A package deal that’s worth it 36
Ambient lighting: Light: the new chrome 38
Development trends with ceramic capacitors: Current measurement in the drive unit of
Hi, we‘re the new guys! 5 electric vehicles: More compact inverters require
NOR flash: Safety for automotive and more precise shunts 40
industrial innovations 8 Haptic feedback systems for touchscreens:
Circuits for miniature loudspeakers: Using touch applications without visual contact 42
Small speakers, big sound 10
• Application
Drive technology:
Pre-charging capacitors using pulse-withstanding
resistors 12
Current sensing solutions:
Concepts for measuring direct current 44
• Inside Rutronik Si vs. SiC MOSFETs:
Exchange technology–but correctly! 48
An interview with Rutronik CMO Markus Krieg: A comparison of electromechanical and MOSFET
“We’ve overcome the crisis well” 14 relays: Analog technology in the digital age 50
Logistics: CO2 sensors based on new measurement principle:
More efficient procurement of C-parts 18 Time to clear the air 52
FAE support: Reference designs, dev kits, and more:
Field application engineers without the field 20 Off-the-shelf is fine,
but nothing beats customization 54
• System technology
Text to speech: Look who’s talking! 56
5G campus networks:
Private cellular networks for the smart factory 22
Alternatives for ToF applications:
How VCSELs can be best put to use 25
Machine learning:
Components for machine learning on the edge 28 • Service
Publishing details 58
5G and TSN:
For the industrial automation of the future 32 List of advertisers 58
4 1/2021 Powered by Committed to Excellence www.rutronik.com
Know-how
Development trends with ceramic capacitors
Hi, we’re the new guys!
There are many demands placed on ceramic capacitors: smaller
construction, large temperature ranges, higher efficiency,
stricter tolerances, optimized functions, and higher frequencies,
not to mention the desire for application-specific versions. The
manufacturers do a lot to satisfy all these requests.
I
n order to continue optimizing their ce-
Figure: Murata
ramic capacitors, manufacturers develop
By Jürgen Geier, Technical Support, new materials and mixtures as well as
and
Pascal Kundelius, Product Sales new approaches to the construction, engi-
Manager Ceramic Capacitors, neering, and interior structure (i.e. the forms
both at Rutronik of the electrode surfaces). They also deliber-
ately make use of certain properties such as
the widely negatively viewed effect of DC
bias. This effect occurs in ferromagnetic ce-
ramic materials such as barium titanate,
which is currently the material most com-
monly used for MLCCs (multilayer ceramic
capacitors).
Alongside the more widely known designs Figure 2: Substitute circuit diagram for variable
such as high-frequency, HiQ, RF, microwave, capacitors.
low-inductance, and low-loss capacitors, a
range of specific and novel ceramic capaci-
tors has recently started appearing on the electrodes, so they could also be referred to
market that are still broadly unknown—given as VACs—voltage adjustable capacitors. These
the current deluge of new developments, this electrically trimmable capacitors are available
is hardly a surprise. We introduce some of with capacitance ratings of 33 pF to 200 pF
the most important features here. for control voltages of up to 3 or 5 V DC, al-
lowing them to be adjusted to up to 50% of
their base capacitance. Compared to regular
Variable capacity
trimmer capacitors, this provides them with
thanks to DC bias
unimagined opportunities—especially given
that they can not only be set to fixed values,
“Variable capacitors” do just as the name sug- but also used to form control loops.
gests—they offer variable capacitance. Using
their DC bias reduces the effective capacities They are available in construction sizes of
when a DC current is applied to their control 0.6 mm × 0.6 mm and 1.3 mm × 0.9 mm for
working voltages of 10 V pp and 30 V pp. Ap-
plications for which these are especially ideal
Figure: Murata
include NFC antenna circuits (13.56 MHz
band), such as those used in smartphones and
check cards, because the variable capacitors
here enable frequency adjustments to be per-
formed by simply applying the appropriate
voltage in conjunction with the NFC ICs. They
also compensate for variance in the antenna’s
L value, making f0 adjustment easier, and also
facilitate debugging during certification test-
Figure 1: “Variable capacitors” offer adjustable capacitance by using DC bias. ing and simplify deviation adjustments during
installation in the housing.
www.rutronik.com Committed to Excellence Powered by 1/2021 5
Know-how
Figure: Murata
range. This is enabled by their lead (lantha-
num) zirconate titanate (P(L)ZT) construction,
referred to as a “ceramic.”
Thanks to their extremely low ESL and ESR,
CeraLink capacitors support higher switching
frequencies and currents. This allows for the
use of cheaper, more robust semiconductors,
for example high-speed IGBTs instead of
MOSFETs. This method often enables the val-
ue of the capacitor, the space on the board,
the magnetic components and the heatsink
to be reduced, thus also reducing the total
cost.
As snubbers, CeraLink capacitors are a superb
solution to reduce the risk of semiconductors
Figure 3: The 3D structure enables miniaturization by a factor of 100. being damaged by voltage spikes.
Thanks to their construction and thicknesses CeraLink capacitors are based on chips
Silicon in the third dimension of just 50 to 400 µm, they are available not (7.85 mm × 6.84 mm × 2.65 mm) from which
just in soldered versions, but also as bonded the manufacturer assembles a variety of con-
For “high-density silicon” or “3D silicon” ca- versions and for embedded installation. This nection options and combinations (Figure 6).
pacitors, manufacturers use the third dimen- means that there are ideal designs available
sion to significantly enlarge the capacitor sur- for automotive, medical, RFID, high-frequen-
Rechargeable solid-state
face—and with it the capacitance—without cy, and broadband applications, categorized
SMD battery
increasing the base surface area of the ca- as standard, high-reliability, high-tempera-
with MLCC construction
pacitor. This is how capacitance values are ture, and high-frequency models.
achieved that would require around 80 layers
in MLCCs with a component thickness of The world’s first rechargeable solid-state SMD
Capacitors with antiferromagnetic
100 µm. battery might not be a capacitor, but the ba-
properties
sic principles of its engineering design, con-
The Murata SiCap, for example, offers a whole structed as an MLCC, are consistent with one.
100 nF with a size of 0402 and a thickness of If ceramic capacitors are used as snubber or “CeraCharge” batteries offer capacitance
just 100 μm—equivalent to ten Class 1 dielec- DC link capacitors in a range of around 500 V around one thousand times that of MLCCs of
tric C0Gs of size 0603 and 400 μm thickness. to 900 V for working frequencies of several comparable physical size. In other words, they
Thinner versions are also available from Mu- hundred kHz up to 1 MHz, MLCCs made of have a comparably high energy density with
rata on request. Capacitance values range X7R ceramics (i.e. those that use the ferro- a minimal volume. Then there are the benefits
from several pF to a few µF, and voltages magnetic barium titanate as their base mate- of ceramic multilayer components, namely ro-
range from 5 to 450 V. rial) are frequently pushed to the limits of us- bust safety and large-scale serial production.
ability. Due to their pronounced negative DC The use of a solid ceramic electrolyte elimi-
Their material and construction properties bias behavior, the necessary effective capaci- nates the risks of fire and explosion, and of
make these high-density silicon capacitors es- tance values in particular are almost impos- electrolyte leakage.
pecially well-suited to high-frequency appli- sible to achieve.
cations from 10 up to 110 GHz. Their electrical CeraCharge supports a very large temperature
characteristics are similar to the known “ce- Antiferromagnetic properties are provided by range of –20°C to +80°C and is therefore suit-
ramic” type NP0 (= C0G). Unlike the C0G the “CeraLink” capacitors from TDK. This able for outdoor use.
MLCCs, however, they can already be used as means that they exhibit an increase in capac-
standard versions up to 150°C, and as high- itance with the applied voltage, which enables The properties open up new opportunities for
temperature versions up to as high as 250°C. much higher currents within the operating CeraCharge, in particular for IoT applications,
Figure: TDK
Figure: Murata
Figure 5: The compact CeraLink capacitors from TDK
are suitable both for use as snubber capacitors and as
Figure 4: A SiCap from Murata offers the capacitance values of ten C0G capacitors with 100 nF. DC link capacitors.
6 1/2021 Powered by Committed to Excellence www.rutronik.com
real-time clock syncing, and energy harvest-
Figure: TDK
ing. If higher currents and/or voltages are re-
quired, these can be provided using parallel
and/or serial circuits.
The CeraCharge is currently available in the
size defined by EIA 1812 (approx. 4.5 mm ×
3.2 mm × 1.1 mm) and offers a rated capaci-
tance of 100 µAh and a nominal voltage of
1.5 V.
Figure 6: CeraLink capacitors are available in many different designs.
Conclusion
Figure: TDK
Even if there are many other optimized
ceramic capacitors alongside the types listed
here, among them MLCCs with internal
copper electrodes, MLCCs with end termina-
tion for conductive adhesives, or “X2Y” ver-
sions, those illustrated here show that it is
worthwhile to be a little more adventurous
on occasion when there are particular re-
quirements. This is useful for you to remain
aware of your options when development is
being performed at a hurried pace, and even
to set new trends with product and device
Figure 7: The construction of a CeraCharge battery is based on the design of an MLCC. designs. ■
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Know-how
NOR flash
Safety for automotive and
industrial innovations
With the advancement of artificial intelligence, machines are being entrusted to
take on more and more tasks. Especially in automotive and industrial applications,
sensors monitor the environment, and algorithms draw conclusions based on the
compiled sensor data. These systems need to not only work correctly to ensure
safety, but also need to make the right decisions—every time, all the time. Modern
NOR flash memory can help achieve this.
S
teering, acceleration, braking and lar controllability, or the ability of a driver or
parking assistance systems, lane de- other traffic participants to prevent damage
By Adrian Elms, Senior Marketing parture warning systems—there are or an accident in a given scenario.
Manager at Rutronik, and
Stephan Wegstein, more and more systems that help us to drive
Senior Manager Product Marketing our cars. They offer greater performance,
NOR flash in safety-critical systems
at Infineon Technologies greater comfort, and greater safety. But in the
latter case, they themselves need to satisfy
strict functional safety standards. These are In numerous advanced driver-assistance sys-
defined in two standards. tems (ADAS), NOR flash memory plays a key
role as part of a safety-critical system, be-
IEC 61508 declares four safety integrity levels cause this non-volatile, programmable mem-
(SILs) for industrial control systems (see table). ory is robust, reliable and fast. The host pro-
ISO 26262, on the other hand, applies to safe- cessor can execute code directly from the
ty-critical electrical/electronic (E/E) systems flash memory without having to copy it to
in automotive vehicles. It defines the safety external DRAM first. This makes NOR flash
levels ASIL A to ASIL D, where ASIL A repre- memory ideal for code execution, not just in
sents the lowest risk potential, and ASIL D the car but also in industrial robots and other
represents the highest. The level is determined IoT machinery and devices. Another advantage
on the basis of frequency, controllability and is its large temperature range, allowing it to
severity of the accident and/or damage. be used in a wide variety of environments and
applications in the vehicle.
ISO 26262 is based on IEC 61508, but specif-
ically accommodates concerns specific to the Common uses for NOR flash memory in auto-
automotive industry. These include in particu- motive and industrial applications include:
Figure: Infineon
The architecture of the Semper NOR flash memory combines an ARM Cortex-M0 with
numerous safety functions.
8 1/2021 Powered by Committed to Excellence www.rutronik.com
• permanent storage of code, data and im- Integrity Level Random Failure Rate Integrity Level Random Failure Rate ages for use during start-up, SIL 4 ≥10–9 to
Know-how
Circuits for miniature loudspeakers
Small speakers,
big sound
“Rrrring, Rrrring”—when every telephone still had a cable, that was
exactly how a phone call would sound. “Ding-dong” was how the
doorbell would herald the arrival of house visitors. Today, users have
a choice of countless songs, sounds, and natural noises. Miniature
loudspeakers with wide frequency ranges make this possible.
By Jochen Neller, Technical Support, and
Anne Santhakumar, Product Sales Manager Acoustic Components & Timing
Devices, both at Rutronik
Figure: PUI Audio
A
udible communication in the form of oscillate. These oscillations create the acous-
speech or music is becoming increas- tic signals perceived by the human ear.
ingly important in human-machine in-
terfaces (HMI), and this is also true of indus- The physics of this type of loudspeaker—in
trial applications. In this field, audible signals particular sound pressure levels (SPL)—require
or announcements can supplement visual in- a certain geometry. This often makes the loud-
dications, especially when information needs speaker a limiting factor that prevents the
to be conveyed despite a lack of visual con- device from being thinner.
tact with the device. There is a selection of
several loudspeaker types for a wide variety
Piezoelectric speakers
of applications. Traditional structure of a ceramic loudspeaker.
A conventional loudspeaker, also known as a Piezoelectric speakers, on the other hand, are
dynamic or magnetic loudspeaker, basically available in thin forms. They do not require a any surface into a loudspeaker, be it a display,
consists of a permanent magnet mounted on voice coil to generate sound—instead, they a table, a mirror, or the plastic housing of an
a voice coil. These in turn are connected at use the piezoelectric effect, whereby the tried application. The PiezoListen generates a high
multiple points. This structure is surrounded and true piezoelectric ceramic material is sound level pressure even at low voltages of
by a loudspeaker frame, which supports a taut usually bonded to a brass or nickel plate and 24 V p-p or less.
diaphragm made of paper, fabric, or plastic. made to vibrate by supplying it with a volt-
age. Unlike dynamic loudspeakers, which Multilayer piezo loudspeakers are triggered
Electrical signals (DC) create a magnetic field measure at least four millimeters in height, and controlled in exactly the same way as a
in the coil, which causes the diaphragm to these are a single millimeter tall at most. dynamic loudspeaker with an IC amplifier.
Construction of a dynamic Another design is that of the multilayer piezo
Amplifier circuits
loudspeaker. loudspeaker. They are constructed not just
from one ceramic element, but multiple
layers, with each layer filtering dif- Amplifier circuits for loudspeakers need to
ferent frequency spectrums. This al- consider three factors in particular: the short-
lows them to generate superior au- term power, the impedance, and the frequen-
dio. cy range.
The PiezoListen from TDK is among the The short-term power—the load that a loud-
thinnest speakers in the world. Measuring speaker can briefly withstand from an ampli-
Figure: PUI Audio
just 0.49 mm in height, it can be glued easily fier signal without being damaged—can range
to smooth surfaces, which are then made to from several 100 mW to several watts in min-
oscillate. This is how it transforms practically iature speakers.
10 1/2021 Powered by Committed to Excellence www.rutronik.comThe impedance of magnetic speakers is usu- A push-pull amplifier consisting of transistors
ally 4, 8, or 16 Ω. It therefore has a significant is a suitable amplifier stage for the audio am-
impact on music output and also plays a ma- plifier. A small high-efficiency speaker only
jor role in the amplifier circuit—if a speaker needs simple standard transistors and elec-
Figure: TDK
with a higher impedance than is recommend- trolytic capacitors to achieve an acceptable
ed is connected to the amplifier, its output volume level.
may be reduced (i.e. the sound becomes qui-
eter). On the other hand, if the impedance is The BCP5616 and BCP5316 complementary
too low, the quality of the sound may be im- transistors from Diodes are well-suited for
paired, or the amplifier may even shut down medium-level output, while something like TDK’s PiezoListen can use its multilayer technology
due to overload. the EEEFK1V101XP from Panasonic is ideal as to transform anything into a loudspeaker.
an electrolytic capacitor.
While magnetic speakers are an inductive loudspeakers complete with housings provide
load, ceramic speakers are a capacitive one. a convenient alternative.
Integrated circuits
This means that they have a much higher im-
pedance, which diminishes with increasing There is often little space available for the
frequency. The amplifier therefore needs to Often, however, it is more effective to use in- loudspeaker, in which case it is important to
supply much greater currents and cannot lim- tegrated circuits to create simple amplifier make optimum use of the available volume to
it the current while maintaining the same circuits. These audio amplifier ICs control and achieve good audio quality with optimum
voltage if the loudspeaker is expected to re- boost the audio signal, providing a louder, sound pressure. This can be achieved with a
ceive signals with high-frequency content. cleaner, and higher-quality sound. They are housing that is as rectangular or cubic as pos-
available in small packages and are found in sible, matching the speaker diameter to the
The frequency range is divided into higher many applications such as televisions, com- front and rear. A horn or funnel also serves to
power classes, so that the signal is sent to a puters, or home audio systems as digital am- amplify sound.
tweeter speaker, mid-range speaker, and bass plifier or operational amplifier types with
speaker. For low power levels, a single wide- mono or stereo audio. Most audio amplifier General rules for the housing structure:
range speaker is used to eliminate the need ICs are specifically designed for dynamic loud-
for audio crossovers. speakers (e.g. NJU8759 from JRC), although • The loudspeaker diaphragm must not hit the
models are also available for piezoelectric front plate at its maximum excursion.
Dynamic speakers have a relatively low effi- speakers with integrated charge pumps (e.g.
ciency level. Their voice coil can be seen as a NJW1280 from JRC). • Vibrations can be avoided using foam be-
permanent resistor connected in series with a tween the speaker chassis and housing. This
high inductance. It produces ohmic losses also prevents the sound from spreading
Loudspeaker
with much of the active power being dissi- from the back to the front.
housing
pated in the form of heat. The amplifier must
therefore provide more power—which is a dis- • A cavity of maximum size behind the speak-
advantage in the case of battery-powered ap- Once the amplified audio signal is at the voice er provides greater volume and superior
plications in particular. coil or the piezo element, sound pressure sound quality. It is often worth having a
waves are generated. When the diaphragm well-designed construction to this end.
In ceramic speakers, their capacitive nature moves forward, a slight positive pressure de-
means that the reactive power plays the velops on the front side of the diaphragm,
Conclusion
greater role, generating little in the way of while a negative pressure develops on the rear
heat. However, the amplifier circuit in the out- side, and vice versa.
put stage requires a large amount of active The choice of speaker type, the amplifier cir-
power, which dictates efficiency here. Instead To avoid cancellations and thus to increase cuit, and the housing can all affect the size
of conventional Class AB amplifiers, other to- the sound level significantly, the front and and audio quality of the speaker. But nowa-
pologies such as Class G or D amplifiers are rear sides of the speaker should be acousti- days, there are solutions available for practi-
recommended nowadays to achieve higher ef- cally insulated, for which the housing must be cally all requirements and construction size
ficiency. designed accordingly. Ready-to-use miniature limitations. ■
Advantages and disadvantages of various speaker designs.
Ceramic piezo loudspeaker Dynamic loudspeaker Multilayer piezo loudspeaker
Advantage Disadvantage Advantage Disadvantage Advantage Disadvantage
High efficiency High driver voltage Tried and true, low-cost Poor efficiency No holes are required for Costly technology
technology audio output
Reproducible production Capacitive behavior Consistent frequency Deep construction Suitable for IP67 case
process behavior
Thin construction Poor handling of bass Ultra-thin construction
tones
www.rutronik.com Committed to Excellence Powered by 1/2021 11Know-how
Drive technology
Pre-charging capacitors using
pulse-withstanding resistors
Electric motors are usually controlled using converters. Electrolytic capacitors
are frequently used to stabilize and buffer the DC voltage in the DC link. There
are a number of issues to consider with switching these capacitors in and out
of the circuit.
W
hen a capacitor is charged through • the internal resistance of the voltage source
a resistor, the increase in voltage estimated at around 20 mΩ
By Bert Weiss, Technical Support follows a curve in the form of a
at Rutronik, and
Roger Renfordt, natural exponential function (Figure 1, blue • the transfer resistance of the connecting
Key Account Manager at Krah line). The relevant charging current of the ca- terminals, switching contacts, etc. of max.
pacitor (green) on the other hand takes the 5 mΩ
form of a decaying exponential function.
This means that a realistic total resistance
The maximum current flows right at the start would be around 50 mΩ. With this, there is
of the charging process, at which point it is still a peak current of over 2,000 A
100 V/50 Ω = 2 A. After around 1.5 seconds (100 V/0.05 Ω = 2,000 A).
the capacitor reaches a voltage of close to
100 V, while the current is close to 0 A. While this very high current would only be
flowing for a very brief moment, you can still
Let’s say this capacitor is charged without us- imagine what impact these current surges can
ing a resistor, so that when the voltage is have on other components—certainly so, when
“hard switched,” there is only a very low spe- you remember that DC voltages of 800 V are
cific resistance in the supply line—estimated commonplace in DC link solutions for convert-
to be 10 mΩ—in which case there is theoret- ers nowadays.
ically a current of up to 10,000 A at the first
moment of charging!
Switch-on processes in consideration of
wire inductance
However, in reality, in addition to the ohmic
resistance of the connecting wire, there are
other elements providing resistance: If we consider not only the capacitance but
also any wire inductance, we observe behav-
• the ohmic resistance of the capacitor esti- ior such as that seen in Figure 3.
mated at around 25 mΩ
Figures: Krah
Figure 1: The voltage and charging current of a capacitor follow opposing natural Figure 2: Charging a capacitor at 5,000 µF to a voltage
exponential functions. of 100 V through a resistor of 50 Ω.
12 1/2021 Powered by Committed to Excellence www.rutronik.comFigure 4: Charging a capacitor at 5,000 µF to a
voltage of 100 V with a resistance of 7 mΩ and a
wire inductance of 7 µH.
Figure 3: Behavior of a capacitor during charging, taking wire inductance into account.
Without going into detail, the graph shows
clearly that the voltage (blue curve) is no lon- Pulse-withstanding pre-charge resistors
ger a natural exponential function, instead
oscillating towards a value of around 100 V. A very simple and cost-effective approach is
Briefly, it will reach a value of up to 170 V, provided here by pulse-withstanding charge
around 70% higher than the externally ap- resistors, which can be connected in series
plied output voltage! with the capacitor for a certain time. All that
is needed here is a pre-charge branch con-
The current (green curve) also peaks at around nected in parallel to the main switch. This
2,100 A just after switch-on due to the addi- branch needs to fulfill the following require-
tional inductance. In other words, the current ments:
reaches very high values and overvoltages
with voltage surges of up to double the ex- • Use of the current-limiting effect of the re- Figure 5: BR, HPRF, and VHPR series pulse-
ternally applied voltage possibly occurring sistor withstanding pre-charge resistors from Krah.
even if all ohmic resistors, inductors, and ca-
pacitors to be charged in the charging circuit • Two-step switch-on process:
are accounted for. 1. The pulse-withstanding resistor is used
to pre-charge the capacitor until it has al- A wide range of pre-charge resistors is offered
This is why hard-switching a capacitor should most entirely reached the externally applied by Krah, the world market leader in power re-
always be avoided. Pre-charging a capacitor voltage level sistors. These include cement-coated wire re-
allows the aforementioned behavior to be al- 2. The capacitor is directly connected by sistors from 3 to 18 W and high-load resistors
most entirely prevented. bridging the pre-charge branch connected with aluminum housing from 60 to 560 W.
in parallel with the main switch Krah also offers customized solutions for spe-
Similar behavior occurs when discharging a cial requirements. For example, increased
capacitor, which is why it is also recommend- • A mechanical or electrical lock-out mecha- voltage requirements, special geometric
ed to provide a resistor for the discharging nism that prevents switch-on without a forms, and also enhanced cooling solutions
process. pre-charge can be implemented. ■
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Unbenannt-1 1 16.04.2021 09:38:02
www.rutronik.com Committed to Excellence Powered by 1/2021 13Inside Rutronik
An interview with Rutronik CMO Markus Krieg
“We’ve overcome
the crisis well”
The pandemic has raged for more than a year now, but
hopes are rising of an end to it. Chief Marketing Officer
Markus Krieg explains in an interview how Rutronik has
performed through the ups and downs, and how the
electronics markets will look in 2021.
Despite the ongoing vaccinations, CO- The lack of opportunities for face-to-face en-
VID-19 will be a part of our lives for gagement and the need to resort to video con-
a long time yet. How well is Rutronik ferencing instead have shown that there are
currently coming through the crisis? areas where digital communication is much
How are store inventories and orders more efficient. This is true not only of cus-
faring? tomer visits—when it comes to digital trade
Comparing the situation to March of the pre- events, we’ve found that leads are qualita-
vious year when the pandemic was beginning, tively and quantitatively on the same level as
it’s fair to say that we’ve overcome the crisis at a live fair. And, last but not least, other
well—both financially and as a workforce. forms of communication are becoming in-
There were few infections and no cases with creasingly important, such as social media,
severe symptoms. This shows how effective which are a much bigger focus now. We are
the measures within the company have been— adapting to this and are much more active in
for example, with our installation measures this field than before. None of this, of course,
and home working. This is the most important means that we’ll be neglecting personal visits,
thing. physical trade events, or traditional forms of
marketing. I think a hybrid form will begin to
But we’re also performing well in terms of take shape from all of this.
sales. 2020 was a challenging year in terms
of sales and order receipts, because many in- The other side is the digitalization of current-
dustries had dialed back their capacities due day applications—we definitely see a shift in
to COVID-19. We noticed a recovery as early this direction. Remote maintenance is playing
Markus Krieg, as the third quarter—incoming orders grew so an increasingly large role, because, of course,
CMO of Rutronik
quickly in October and November that we re- I can’t always send technicians to every cor-
ally struggled to meet demand. In fact, No- ner of the globe at a moment’s notice. In
“ We are taking our own vember 2020 dropped an all-time record in terms of products, we are seeing strong
„
terms of incoming orders into our laps—and growth in communication ICs—they are basi-
patent to all of the major OEMs, we were pleased to note that this trend con- cally a factor in every application and offer
one that is of particular interest tinued in January and February. enormous growth potential, which in turn
for hybrid vehicles. means a massive push towards digitalization.
The COVID-19 pandemic has accelerated
the process of digitalization in many ar- How can Rutronik help to overcome the
eas—including industry. How persistent COVID-19 crisis in the current situation,
will this shift be, and what does this outside of its core business?
mean for Rutronik’s business model? We are, naturally, studying the current situa-
It’s important to see this as two different tion and examining how we can help. With
trends. Firstly, there’s the digitalization in per- our excellent contacts with Asia and the lo-
sonal communication, and secondly, we have gistics capabilities that this entails, we can
digitalization in the development of applica- help to bring rapid tests and FFP2 masks to
tions. Europe, for example, and in this way help the
14 1/2021 Powered by Committed to Excellence www.rutronik.comgovernment to achieve their targets of more BMW to Audi. But if I do that, my supply chain
frequent testing. In Pforzheim, we are also us- ends up sitting on its products—and without
ing our logistics capacities to support the much warning. This means masses of cancel-
large-scale testing center—the goal here be- lations and delays—at one point, Rutronik had
ing the “Tübingen Model,” which aims to re- to manage and process up to 200,000 order
store public life to a relative state of normal- item changes in a day. When the market re-
ity with a large number of rapid tests. We are gained pace, they were surprised that the sup-
also assisting in the development of an app ply chain had distributed the semiconductors
that is another element of this concept. elsewhere and the capacities were no longer
available. I can’t bring myself to point fingers
Europe’s share of the demand for global at the supply chain or component producers H
High-Current
igh
h-Cur
electronic components is dropping to here because the automotive industry did a C
Contact
onntact E
Elements
around 8 percent—which basically cov- poor job of resource management in this case.
ers Apple’s or Samsung’s needs alone. Right now, this has given rise to the problem
This will have consequences for the sup- of our being unable to purchase components
ply chain, in which European businesses as quickly as the customers are ordering them.
risk falling behind in the medium and We’ve been able to manage so far, or at least
long term. How can Europe gain an ad- our customers haven’t suffered a line stop just
vantage here, and how can distributors yet. To this end, we communicate closely with
help? OEMs and Tier One and Tier Two representa-
To put it bluntly, the European Union has tives. We hope to be able to meet demand
spent years blissfully asleep at the wheel, and normally again by the end of Q3 or early Q4. versatile application possibilities
never noticed that they are becoming tech- Until then, though, we have two quarters with in compact control units and
nologically extremely dependent on Asia and a lot of backlog management to handle. Our
on-board charging modules
the USA. The remaining European semicon- analyses have shown that the incoming orders
ductor manufacturers that essentially matter to date are basically what wasn’t ordered last
have developed their own production capaci- year—in other words, we started at a very low
ties in Asia or have turned to third-party pro- backlog level, and the incoming orders are fill-
ducers. The consequence of this has been that, ing our books to the level that we would have
even if we develop the IP and the associated expected without COVID-19 in 2020.
mating with contact tab,
technology in Europe, it doesn’t mean that we
can get the production capacity for the rele- Are there other component groups where top or bottom entry
vant chips in Asia. The EU and the German allocation is to be expected? And how
government have now finally woken up and well is Rutronik prepared for this?
set up a scheme to boost Europe’s own semi- In light of the circumstances described above,
conductor production—for which 150 billion we basically have shortages in every area. Is-
euros are on the table. As the third-largest sues with logistics and transport capacities
distributor in Europe, Rutronik is on hand with exacerbate the matter. The markets have re- for SMT soldering
its expertise—we are in talks with top-level covered with a time delay—China resumed
representatives of the EU and the German producing earlier and has exported a lot to or welding
government. But bringing production capaci- Europe and America. This has shifted contain-
ties back to Europe is not the end of the sto- er capacities to these regions, and these ca-
ry—we need to ensure that European distribu- pacities are now lacking elsewhere. The few
tion channels make use of these production available containers are currently being rent-
capacities, and that they can distribute the ed for three times the normal price, mainly
production output to customers in Europe. We from the US, meaning that we in Europe have
aim to ensure that Vishay, Infineon, and the very little in the way of transport capacity.
smaller manufacturers that are still in Europe This makes it difficult to quickly respond to
are compelled to focus on Europe with their shortages.
distribution channels.
Specifically, this affects products such as dis-
Rutronik generates just under half of plays and wireless modules. We try to keep
its sales from the automotive sector. production running by ensuring daily commu-
And car manufacturers and their suppli- nication between customers and suppliers. from 65 A
ers are also starting to feel the pinch of With passive components, we occasionally ex- up to 80 A
component allocation. How is security of perience shortages of electrolytic capacitors,
supply looking for Rutronik’s automo- which is due to the massive development of
tive customers? the 5G network, which requires a very large
It’s worth looking at the wider picture here. number of capacitors. The shortages are also
In April/May 2020, the OEMs started massive- being exacerbated by the rapid development
ly dialing back their production, from VW to of electromobility, which is expanding faster
www.lumberg.com
www.rutronik.com Powered by 1/2021 15Inside Rutronik
than expected. This increases the demand for The catch lies elsewhere, namely in legal and ment. So a comparison isn’t quite that simple.
electrolytic capacitors, coils, and inductors— ethical matters—questions of “do I really want Higher margins are important for us because
but even with electromechanical components, to hand decisions of how to react in a dan- we have a high cost of ownership due to our
there are still occasional shortages, for ex- gerous situation to a machine?” and “What’s passive and commodity portfolio. There are
ample plug connectors for electric or hybrid the position of insurers on this?” three key strategic points. Firstly, we must
vehicles, although not to the extent seen in show manufacturers that they benefit from
2018. Delivery times have also increased for How is the market performing in America our business model, because we provide them
ceramic capacitors and automotive-certified and Asia, and what are the differences to with access to an additional customer group
products, although there’s no talk of compo- Europe? by delivering commodities to them. Secondly,
nent allocation just yet. Our Asian business is performing wonderfully. we prepare our product marketing, sales, and
Asia in general, and in particular China, over- FAEs even more effectively with training mea-
came the crisis much sooner, which has had sures. And thirdly, we establish a very broad,
“
a positive impact on our overall net income. balanced customer basis. Especially in the
When it comes to digital trade The first three months of this year were very mid-range segment, there are entirely differ-
„
events, we’ve found that leads are qua- encouraging—not just in China, but in South- ent opportunities to generate margins com-
East Asia, too. The situation in the US is rath- pared to the Tier One and Automotive seg-
litatively and quantitatively on the same er more challenging, and we’ve had to cut jobs ments.
level as at a live fair. in the midst of the COVID-19 pandemic, so
we’re rather thin on the ground staff-wise Finally, let us take that ever-dreaded
there. We also don’t yet have the resources on look into the crystal ball. How will 2021
the ground that we wanted available at the develop for Rutronik and for the elec-
What is your take on the situation of US headquarters. This makes it difficult to de- tronics industry as a whole?
German OEMs and suppliers given the velop the business in a way that allows us to I believe that two things will be important for
upheaval caused by electromobility? achieve reasonable profitability. Mexico has the rest of the year. The first is availability—
How is Rutronik supporting its custom- also been severely hit by the coronavirus, and for responding quickly to changes, for man-
ers with this? this is why our customers’ factories were aging existing backlogs, and thus to generate
For us as a component distributor, electrifica- closed for weeks, if not months. as much business as possible. The other is the
tion is, of course, a positive thing, because we matter of the impact of COVID-19—right now,
participate in it. The share of components in How is Rutronik Analytics performing? many hope that the vaccines will enable us to
the vehicle will increase in electrically pow- We’re very happy with it. The analyses that make great strides towards normality in Q4.
ered vehicles than is already the case today, we have performed using the tool to date have I’m a little more skeptical about that, not least
especially in terms of semiconductors for been very successful. We have set up a dedi- because of the mutations and the different
high-performance drives and power electron- cated team to offer the services offered by effectiveness levels of the vaccines. We have
ics. We engage with our customers closely in Rutronik Analytics now to customers as well. a close eye on developments so that we can
this regard and introduce them to innovations We are also continuously evolving on a tech- be prepared for all eventualities. If things are
to enable them to keep pace with non-Euro- nological level and are trying to become less looking up, we will, of course, be pleased and
pean competitors. dependent on a single service provider, to de- will help where we can. But even if things take
velop in-house software development re- a turn for the worse, we have learned from
Another area relates to batteries. We are tak- sources, and to further improve our analysis the past and are prepared to take the neces-
ing our own patent to all of the major OEMs, IP. sary steps as a company.
one that is of particular interest for hybrid
vehicles. It allows the same distance to be We managed to get through the crisis in 2020
covered with fewer batteries than was previ- without cutting working hours. This proves
“ „
ously possible, which in turn helps save costs. Our analyses have shown that the that the measures we took were the right
We expect the first cars using our patent to ones—including from a financial perspective.
be on the road in two years. But we’re not fo- incoming orders to date are the result of We have created a foundation that enables us
cusing solely on e-mobility—we also have what wasn’t ordered last year. to respond appropriately to all situations. We
faith in fuel cells, and we have customers must never forget that to profit from strong
we’re supporting in this field as well. growth in business, you need the financial re-
sources to adjust to it. We have prepared our
And what about autonomous vehicles? Distributors’ margins have been falling business accordingly. ■
As far as autonomous driving is concerned, we for years. How has COVID-19 affected
can see with Google or Tesla that it is already this? Are there new developments in the
broadly possible today. The 5G network pro- market or within Rutronik?
vides the requisite communication infrastruc- To begin with, falling margins are a psycho-
ture, not only for autonomous driving but also logical problem. If I’m worried about losing a
for car-to-car communication. This is a mas- contract in adverse times, I can’t go into ne-
sive opportunity for us, not only in relation to gotiations with the self-confidence I need.
communication semiconductors, but also in This is why we had a drop in margins in 2020—
power suppliers for transmission towers—the although 2019 was itself a year that suffered
demand here is enormous. partially from allocation in the passive seg-
16 1/2021 Powered by Committed to Excellence www.rutronik.comIN CHARGE OF TOMORROW In the market for electric vehicles (EVs), which are expected to grow even further in the future, JAE has been working on the development of connectors for EV charging since 2010, the early adoption of vehicles. We have already commercialized products (KW Series) that conform to CHAdeMO and CCS Type-2 standards. Currently we are developing new products that conform to CHAdeMO with the aim of further strengthening our line-up. Connect with JAE - and profit from innovative, reliable and responsible electric mobility solutions. Don't wait for the future, but shape it!
Inside Rutronik
Logistics
More efficient procurement
of C-parts
Customers ordered over 71 billion commodities from Rutronik in 2020. For the
majority of these components, it is important to view the huge volumes in the context
of their prices, which are often just a few cents or even fractions of a cent—these
are referred to as C-parts. To generate savings potential here, it is therefore more
beneficial to examine the order processes than the price of the goods themselves.
L
et’s say a business needs 40,000 chip price adjustments through annual price ne-
resistors each month. To keep store in- gotiations.
By Roman Wolf, Project Manager ventory low, an order of 10,000 resis-
Supply Chain Solutions, and
Patrick Krätz, Head of Supply Chain tors is sent each week. This means that four
Potential for optimization
Solutions, both at Rutronik times a month a worker has to unpack the
goods, check the delivery note, enter the de-
livery note into the inventory control system, To reduce process costs, delivery volumes and
and then shelve the goods. So as we see, com- packaging units are effective tools for opti-
ponents that are themselves worth just a few mization. Many commodities are available in
euros cause process costs that are at least packages of 5,000 to 50,000 units, usually on
equally as high—if not higher—than the prod- a reel. The rule to consider is this: the bigger
uct’s actual worth. The potential to cut costs the selected unit, the lower the process costs.
is therefore much higher in this area than with If the company in the above example were to
Figure: nordroden/stock.adobe.com
18 1/2021 Powered by Committed to Excellence www.rutronik.comorder 40,000 chip resistors once a month in-
Figure: Rutronik
stead of 10,000 units four times a month, the
required expense and effort would be reduced
to just a quarter. While this increases store
inventory, the low value of the C-parts means
that this is not usually a relevant factor.
With optimizations such as these, Rutronik
has been able to drastically reduce the num-
ber of delivery note items for numerous cus-
tomers whose annual order volumes number
in the billions of units (see image), or has
managed to keep these items consistent while
volumes rise. And each item removed from the
delivery note represents process costs saved.
Security of supply with low storage costs
Optimized procurement allows for drastic cuts in the number of delivery note items—and with these,
a reduction in the effort and expense required for the receipt of incoming goods.
If the main concern is a low stock value, a
consignment store is a good way to keep this tomers as possible to benefit from electronic common, whether due to adverse weather
value low. The goods are stored near to the data interchange and, with it, the ability to conditions in regions with large numbers of
company’s production facilities, ready to be automate procurement processes. This results production sites, the impact of the COVID-19
collected as needed. They are only billed when in an improvement in data quality, basically pandemic, or demand surges resulting in al-
collected. This is how a consignment store of- as a by-product. location, as was the case in 2018.
fers not only low storage costs but also opti-
mized management of goods flows, as well as This is true both of conventional procurement Logistics is much more than just ordering the
security of supply. processes with order submissions and order right goods at the right time to be delivered
confirmations as it is of dynamic delivery sys- to the right place. It is also an essential ele-
To make procurement processes generally as tems involving rolling, long-term forecasts. ment of optimizing cost structure and of the
efficient as possible, Rutronik had taken steps The latter in particular also contributes sig- performance of the company. For C-parts, ef-
years ago to digitalize the entire process, from nificantly to security of supply, because the ficient delivery processes play an especially
order to forecast to shipping notification to more familiar the distributor is with the long- important role in keeping logistics and pro-
invoicing. In addition to standardized file for- term needs of its customers, the better they cessing costs as low as possible, even as vol-
mats such as EDIFACT, VDA, or SAP IDOC, can take account of these needs in the event umes rise. This is why a customized, smart
Rutronik can also handle other formats, such of sudden market changes in the manufac- delivery strategy makes more sense here than
as Excel or text files, enabling as many cus- turer backlog—a situation that is extremely a just-in-time delivery system. ■
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www.rutronik.com Committed to Excellence Powered by 1/2021 19Inside Rutronik
FAE support
Field application engineers
without the field
Sitting at a table with developers feels like a thing of the past. Design-in
support is another thing that the coronavirus pandemic has largely relocated
into the digital realm. What can still be achieved with it? And what form will
it take in the post-corona era? Carsten Steiner, Director FAE/BDM Global at
Rutronik, provides the answers.
Mr. Steiner, what can be achieved with That’s not quite true. Sure, you might be able
digital FAE support? to find a lot of information, but it can easily
Carsten Steiner: I’ll start with what it can’t take hours to find what an FAE could answer
achieve—it doesn’t let us test components in a few minutes. Not only that, but you need
under real conditions with our customers. to be able to understand the context of the
And the intuitive hands-on experience is also information, which takes knowledge and ex-
lacking, especially with many electrome- perience. Each of our customers is an absolute
chanical components. Displays are something expert in their field, no doubt about that! But
Carsten Steiner, Director FAE/BDM Global at
that you need to have seen in person before their core expertise is not in the continuous
Rutronik
“
you choose to buy them—even the glossiest and intensive observation of the component
„
brochures, websites, and data sheets won’t market. This is a time-consuming task that our Ultimately, the goal is always
suffice here. This is why we have a compre- FAEs perform by actively engaging with the
to develop a competitive final
hensive warehouse with demo products that component manufacturers and with the col-
our customers can borrow and test in their laboration of our product and line managers. product.
application.
This is in part time-consuming because the
And the personal aspect of face-to-face diversity of product models and the complex-
meetings is also missing. Digital meet- ity of the components has massively increased for years, even though these components have
ings are simply not a full-blooded sub- in recent years, while life cycles continue to since ceased to be technologically relevant or
stitute for them. be ever shorter. It’s not enough to be familiar have ceased to represent a major cost factor.
But everything else works just as well online— with the latest components—the manufactur- Others end up left unnoticed, with the same
some of it even better, in fact. We keep dis- ers’ road maps are also important. Being un- components being used again and again, even
covering that we are often able to answer our aware of these may result in a component though there is considerable optimization po-
customers’ questions more quickly in Web being incorporated into a design, even though tential for the solution as a whole. With an
meetings than we can during on-site appoint- it has already been discontinued when serial outside perspective and backed by a compre-
ments. In this regard, our FAEs prepare for ev- production starts. Our FAEs always have an hensive product portfolio, our FAEs can take
ery meeting even more intensively than they eye on this, and on delivery times. To avoid a holistic perspective of the solution and con-
ever have. In the future, we aim to make use unpleasant surprises, they also recommend sider the total cost of ownership.
of other communication methods and tools alternative components as a second source—
such as messaging services, ticketing systems, and not just with focus components, either. And there’s another very important aspect:
and virtual/augmented reality solutions. This C-parts are just as prone to causing produc- time to market. The points that I mentioned
is how we aim to engage with our customers tion stoppages, as recent months have shown all help to ensure a rapid market launch. We
on an even more individual level—a beginner time and time again. It is also important to be also support our customers with in-house-
and a digital native simply has different ex- able to assess the opportunities and limits of developed development kits, demo boards, and
pectations and preferences to a veteran with components, which takes experience, and also complete solutions, for example with an MCU
decades of experience. knowledge of the latest technologies. These platform for AI-based edge applications.
often enable entirely different solutions for
If everything is done online anyway, certain requirements. You mentioned short development cy-
can’t a developer or purchaser simply cles. Which product segments are see-
use Google, search through an online You can’t just google all of this. And what’s ing the most dynamic performance?
shop, or ask in forums? I mean, you can more, we often notice how component deci- I would say that everything in the Wireless
find everything online these days. sions have focused on the same components segment is among them. The new wireless
20 1/2021 Powered by Committed to Excellence www.rutronik.comYou can also read
