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Questions tagged [reliability]

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How do I select a correct BGA underfill?

Several products we manufacture use fine (0.4mm) pitch BGA devices. In order to improve reliability, we are (by hand) applying BGA underfill to these devices. This is a type of adhesive which flows ...
Rocketmagnet's user avatar
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1 vote
1 answer
76 views

PCB footprint design for minimum solder use [closed]

Are there any studies that show how to design a footprint for minimum solder use? I'm looking at an application where many millions of solder points per day will be running. Obviously there's a ...
user103218's user avatar
0 votes
4 answers
97 views

Are voltage ratings defined differently for capacitors and light bulbs?

The voltage rating of a capacitor is the maximum operating voltage, while the voltage rating of a light bulb is its normal operating voltage. Are there two different definitions of voltage ratings, or ...
hana's user avatar
  • 290
0 votes
3 answers
83 views

Concerns about Exceeding Current Rating on SN74HC595N to drive LEDs

I am currently working on a project where I am utilizing SN74HC595N shift registers to drive multiple LEDs. According to the datasheet, the maximum output per pin is specified as 35 mA, with a maximum ...
HydroPage's user avatar
3 votes
2 answers
94 views

How to add "cold-reset" MOSFET to a I²C chip? Should it be a P-MOS or N-MOS?

Background I have a device which sports a couple of "IMU" chips - ICM-20602 and LIS3MDL - which both do not have reset functionality on a pin. They do have the ability to be rebooted by a ...
anrieff's user avatar
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0 votes
1 answer
35 views

How do you choose the right load for reliability testing?

I am an automotive reliability and test engineer. I do environmental or electrical tests and during these tests I need to load my products. By load I mean, for example, there is a mosfet driven by a ...
Taha Füzün's user avatar
0 votes
0 answers
32 views

MIL-HDBK-217F-N2 asks for # of gates and/or transistors

New to the whole reliability prediction using MIL-217F, was wondering whether anyone had an advise/suggestion/best-practice/wisdom on how to determine the number of gates and/or transistors from a ...
Martinho Luterinho's user avatar
0 votes
0 answers
63 views

Reliable fail-safe optoisolator

I would like to add an extra fail-safe to a optocoupler. My current approach is to transmit a pulse of very specific frequency and pulsewidth on a clock on the high voltage side through the ...
user338269's user avatar
18 votes
2 answers
2k views

Why is a MEMS device affected by helium but not hydrogen?

It seems that MEMS is very sensitive to helium, but only helium. This Link stated that hydrogen does not affect MEMS, which surprised me. Does anybody know why it's just helium, or what's really going ...
MicroservicesOnDDD's user avatar
2 votes
2 answers
735 views

How reliable are screw terminal blocks when the connected cables are allowed to sway a little bit?

2.54 Screw terminal blocks are a really convenient way to wire up devices without the need to solder a port or a jack connector. However, with all their convenience, how reliable are screw terminal ...
Noideas's user avatar
  • 109
8 votes
4 answers
990 views

Should I protect against collapsing field effects of a microcontroller-driven small-signal relay coil?

I am building a simple engage/bypass switch for musical (e.g. electric guitar) effects. The signal switching will be done by a single coil (bistable) latching relay, such as the Panasonic TQ2-L-5V. ...
Matt's user avatar
  • 187
0 votes
2 answers
75 views

High reliability, automatic reset, enable switch

I am currently facing the issue that I am currently working on a subsystem for a high power industrial automation system. The panel of this subsystem consists of a lot of components, however here only ...
user338269's user avatar
2 votes
1 answer
36 views

Output agreement with \$n\$-bit TMR majority gates

I am currently researching triple-modular redundancy implementations and majority-gate voting logic and I'm wondering how the canonical single-bit majority voters found in textbooks are scaled up to ...
ecfedele's user avatar
  • 617
5 votes
2 answers
467 views

Radiation tolerance of MCUs

I'm working on a cubesat project intended to operate in low earth orbit. We're considering a few different options for our flight computer, ranging from Raspberry Pi to something like STM32L476. ...
crossroad's user avatar
  • 1,430
0 votes
3 answers
116 views

How to calculate Bit Error Rate of an electronic equipment with several parts?

I am currently studying integrity of data into electronic systems facing Single Event Effects. I am focusing on data integrity inside an electronic equipment. I've been through a lot of papers ...
lordlothard's user avatar
0 votes
5 answers
447 views

Failsafe for relay contact welding

So, I'm fiddling with a design for a widget, and one of the "fun" parts is to ensure that power is reliably cut without human intervention. Power is normally controlled by relays, which have ...
Matthew's user avatar
  • 572
20 votes
7 answers
4k views

Is "automotive" grade always better?

I'm working on the parts list for a number of designs for low-voltage (24 VDC) industrial circuits that have no special safety requirements: so long as they don't catch fire no one could be hurt nor ...
jonathanjo's user avatar
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2 votes
0 answers
83 views

Brief short circuit effects on long-term reliability of a battery

I have ten 220uF ceramic capacitors across a 3.7V 18650 li-ion battery. The total 2200uF therefore effectively shorts out the battery for about a millisecond every time I insert it. Is this ...
bobuhito's user avatar
  • 544
5 votes
2 answers
120 views

Classifying levels of dust and dirt inside power electronics

I have a fleet (100+) of 100 kVA and above uninterruptible power supplies across the UK. They are designed to be super reliable. I work as the "reliability engineer" so local engineers ...
scc268's user avatar
  • 176
0 votes
3 answers
131 views

What are the invisible reasons why many discrete transistors do not qualify for automotive use?

I looked today at the datasheets of this unqualified and this qualified product (per the AEC-Q101 automotive standard) and found no substantial difference, but I assume some stress damages only the ...
bobuhito's user avatar
  • 544
3 votes
1 answer
117 views

Impact of transistor gate connected directly to a supply net/ internal supply

The risk of connecting gate of transistor in analog design is not very much in latest process technologies. But what is the impact of connected gate to power net unintentionally? Will it damage the ...
Alan Saldanha's user avatar
1 vote
3 answers
840 views

GPIO with no pullups or pulldowns

I have a SPDT switch connected to a GPIO pin on an nRF52810 microcontroller. The switch has two positions: Shorts the GPIO to GND Shorts the GPIO to V+ The switch is used to toggle a software ...
Chris Fernandez's user avatar
7 votes
2 answers
795 views

How do the electrical characteristics of an ADC degrade over lifetime?

How do the electrical characteristics of an ADC typically degrade over lifetime? And is there a way to do a somewhat realistic worst-case estimate for that before doing aging tests over a big batch? ...
Torsten Knodt's user avatar
7 votes
3 answers
2k views

How did the vacuum tube computer technicians know when a tube had failed?

I have read that in vacuum tube computers, a tube would fail every couple of days. How did the technicians know that a tube had failed? Wouldn't a broken tube silently cause the calculations to ...
Andrey Bienkowski's user avatar
0 votes
1 answer
271 views

I2C Hot Swap design and feasibility

I would like to hear if someone has successfully implemented a working connectable/disconnectable I2C interface. I'm working with the back plane (host device) and am looking into implementing a I2C ...
NoobPointerException's user avatar
1 vote
1 answer
73 views

If a motor driver IC has shoot-through protection does the controller need to add deadtime?

I'm designing a motor driver and controller system for an E-Bike, and I'm currently using the IRSM836-084MA. The datasheet mentions that it has "cross-conduction prevention logic", but to my ...
shraiwi's user avatar
  • 21
0 votes
3 answers
212 views

PFHD of Dual Redundant Self Checking Circuit

I'm calculating some ridiculous PFHD values for a Dual Redundant Self Checking Circuit and since I'm no expert in reliability calculations (cough) I wanted to check some of the logic. I have two ...
user1228123's user avatar
1 vote
0 answers
41 views

How can we model the piezoelectric behavior of a capacitor to mechanical and thermal transients?

I would like to model the behavior of ceramic capacitor to thermal and mechanical stress. We are seeing power supply fluctuations during reliability test and suspecting the ceramic capacitors' role in ...
Dynamic_equilibrium's user avatar
11 votes
4 answers
1k views

Soviet-era mounting techniques to absorb vibration (THT components)

This question is about a historical point of view. I was watching this video about a Soviet-era dialer. As many Russian devices of that time, the construction is simple and in some aspects strange (...
gino's user avatar
  • 489
3 votes
1 answer
443 views

Why do speed sensors fail so often?

The typical vehicle speed sensor (variable reluctance sensor) is a very basic device which essentially amounts to a coil of wire wrapped around a permanent magnet. Simple, yes, but very reliable? ...
Redgum's user avatar
  • 133
4 votes
2 answers
353 views

When to use a high voltage resistor vs multiple standard resistors?

Looking for the smallest & most reliable method of dropping 360V down to ~1V for a PMIC feedback pin. Reliability is probably the most important variable here. Question: In general are we be ...
MadHatter's user avatar
  • 3,536
2 votes
1 answer
178 views

Should I be worried about the possibility of a microcontroller failing?

I'm making a commercial product for the first time and I am worried about the stability of my circuit over time. The product is a door interlocking system. It locks and unlocks doors using solenoid ...
Pouria P's user avatar
  • 320
2 votes
2 answers
300 views

Reliable connection for thin wire

I am searching for a reliable wire-to-board connection. The wire is 0.1 mm enamelled wire. The wire is solderable, but the polymer is very temperature resistant and needs to be mechanically removed ...
Conrad's user avatar
  • 21
1 vote
2 answers
305 views

Power source redundancy for low voltage application

I am trying to design a circuit that u would like to be as reliable as possible. One feature I would like to add to my circuit is an additional voltage regulator for redundancy purpose. The problem is ...
user127515's user avatar
0 votes
3 answers
571 views

The Mean Time Between Failure (MTBF) Quantity

It is the amount of time a system is operational i.e. MTTF plus the amount of time to repair it MTTR. I am considering repairable systems only. I know that it helps in scheduling maintenance, safety ...
OMAR's user avatar
  • 883
0 votes
1 answer
63 views

longer reliability in power systems

The highlighted term "longer", I think it should have been lower. What is longer reliability?
OMAR's user avatar
  • 883
0 votes
0 answers
86 views

STM32L4S9 low temperature FLASH memory programming

As there is no information on the internet I hope that I will not have any problems (as there are no complaints :) ). My device will receive OTA updates and my question is: Did you have any problems ...
0___________'s user avatar
  • 2,594
0 votes
2 answers
108 views

THT components reliability and advantages for small scale production [closed]

Examining this question in the "manufacturing of not consumer electronics". I'm looking for an opinion by others about some statements that I take for correct. Are THT components in general ...
gino's user avatar
  • 489
0 votes
1 answer
163 views

Can an n-channel mosfet gate be held closed for months at a time and still reliably open when Vin falls below threshold?

I made a prototype circuit to detect the loss of individual 12V lithium batteries in a larger parallel bank due to BMS cutoff (12V continuous signal from an individual battery suddenly becomes open ...
VanGogh66's user avatar
  • 301
0 votes
0 answers
107 views

Which is more robust against temperature cycles, solder or wire wrap?

When connecting a bunch of components in something that will be subject to repeated heating and cooling, are soldered joints likely to be more or less robust than wire wrap? Intuitively, it feels like ...
rwallace's user avatar
  • 563
3 votes
1 answer
159 views

Calculation for IC lifetime for supply voltage overvoltage

What calculation can be used to calculate the lifetime of an embedded processor (<28nm process) when subject to a slight overvoltage? The supply rail in question is for analog portions of the ...
Jack Bourne's user avatar
3 votes
2 answers
568 views

Mosfet thermal problems in linear applications

Modern power FET's can be unreliable in some linear applications due to thermal instability causing die hotspots and premature failure. This is called the Spirito effect. How do Silicon Carbide ...
Autistic's user avatar
  • 14.9k
22 votes
5 answers
4k views

How can we test the lifespan of electrical components?

We work with some electronic devices in our projects. We are at the stage where we need to create some test strategy to validate the lifespan (e.g. 1 to 5 years) of our devices for which we provide ...
MKSJ's user avatar
  • 229
4 votes
4 answers
146 views

Relay - Doesn't work....at first

I have a latching small signal <2A relay (V23079E1201B301) that switches between two audio signals. The relay has worked in about 10k boards over 7-8 years without much issue. We recently got a run ...
jfee's user avatar
  • 41
0 votes
0 answers
41 views

Durability of SMD MEMS pressure sensors in pure oxygen enviroment

I have a question regarding durability/reliability of COTS SMD mems pressure sensors in oxygen rich (basically 100%) atmosphere under pressure of 1bar/1atm and temperature around 20C/293K. Sensor ...
Felix's user avatar
  • 133
0 votes
0 answers
307 views

Latching Priority Encoder, circuit works but I don't trust it

I added a schematic even though the question is actually too simple for it. The datasheets for the devices are likely to be more revealing. The circuit is super simple. I have a 74HC148 priority ...
DarylK's user avatar
  • 203
0 votes
0 answers
56 views

How to detect brushless DC motor wear?

The manufacturer of the brushless motor does not specify a lifetime for the particular motor I am using (BLDC5-R-57BL120L2.) For my application it is essential that the axial and radial movement of ...
kva's user avatar
  • 440
1 vote
1 answer
701 views

Base-emitter reverse breakdown and current

I have a circuit as follows, simulate this circuit – Schematic created using CircuitLab which provides a control current to an OTA as \$i_\mathrm{abc} = (3.27\mathrm{V} - V_\mathrm{in})/R1\$. ...
Timo's user avatar
  • 1,179
0 votes
0 answers
330 views

How does manufacturer determine initial tolerance for capacitors?

Short version: I understand resistor initial tolerance is commonly obtained through sorting process where manufacturer only picks resistor that has resistance within the advertised initial tolerance. ...
brokenegg's user avatar
0 votes
1 answer
1k views

Turn off MOSFET with diode - PWM controller Maximal output current

Here is my circuit (and I know that this circuit does not cause any problems at least for the moment): For turning on, the maximal current from the pin "OUT" is limited by the resistance ...
Jess's user avatar
  • 2,448