Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [diode-clamp]

125 questions
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12 V input on 3.3 V GPIO, TVS pulled down or Schottky pull up?

I am building my own PLC that has to accept permanent inputs of up to 30 V DC into a STM32F with 3.3 V inputs. The switched input will have to work with 8-30 V, but 90% of the time the input voltage will be fixed at 12 V or 24 V. Inputs will only…
Newbie Noob
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FPGA over-voltage protection for input trigger signal

I don't have much experience with PCB design, but I am currently designing one to connect together several components for a work project. One of these components is connecting an external trigger signal to an input pin on a Neso Artix 7 FPGA board.…
hexahedronest
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How to choose the correct TVS diode and how to size it?

So I was thinking about transient suppression and I found TVS diodes. I was wondering how to choose the correct TVS diode since they have 3 voltage parameters: Vc --> clamping voltage, voltage I think you want to cut the transient spike. the…
Suvi_Eu
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TVS diode specs - clamping voltage lower than breakdown voltage?

Having read this app note (and a few others) and quite a number of TVS datasheets, I came across one that is bugging me a bit. All of the TVS datasheets that I have read so far describe the the following concept (below curve is for a unidirectional…
wave.jaco
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Aternative diode classes for high frequency(10GHz) applications

I'm trying to design a voltage clamping circuit for a 10GHz signal. I've modeled it in spice using several schottky diodes and it works but only when the signal pulse is at least a few nanoseconds long. In my case I need diodes that can handle a…
user51404
5
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1 answer

Can a ggNMOS be implemented discretely on a PCB?

Reading this answer, I ran across the ggNMOS for ESD protection. https://electronics.stackexchange.com/a/576935/166672 Reading on the web a little, it seems that this is only used inside of an IC, not at the PCB level. However I do not see any…
Aaron
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What is the purpose of clamping the gate and source of a mosfet

Is clamping the gate and source of a MOSFET really important? I have seen this in some articles and some datasheets of MOSFETs where they have built in clamping. As far as i know they are used for ESD. Asuming that the gate is just a trace to a…
Jake quin
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Analog input over-voltage protection using Schottky and Zener Diodes. Can it work?

I'm developing an analog input module based on TI's ADS8668 and want to protect the input channels from over-voltage. According to the datasheet, each analog input channel withstands voltages from -20V up to +20V. Although my analog signals are…
ser_u
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3 answers

My IC keeps blowing up - PAC1720 current sense IC

I am using a PAC1720 current measuring IC to measure the current/voltage/power being delivered to a lead acid motorcycle battery that is being charged. Here is a newer datasheet and an older datasheet (with different info in them!) Everything seems…
macdonaldtomw
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Over voltage and reverse voltage protection of multiplexed ADC with voltage follower

I am designing a protection circuit for the ADC section of a design I am working on. There will be 8 analog signals being read by a single pin of the MCU via an 8 channel multiplexer. The analog signals each go through a voltage divider such that…
macdonaldtomw
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"A zener with series diode"?

So I'm still reading The Art of Electronics Third Edition. On P.39, when dealing with inductive "kick", I found this sentence: For the fastest decay with a given maximum voltage, a zener with series diode (or other voltage-clamping device) can be…
nalzok
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Possible wrong use of TVS diodes?

I've been facing a weird situation and unable to find the reason behind so far, therefore I frustratedly turned up for help. I have a system comprised of 2 separated PCBs (A control box and an on-board controller), connected through a thick 10-pin…
Thomas Lin
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Diode-connected BJT vs base-emitter BJT diode vs diode

I was having a look at the circuit design of Keithley 236 SMU. You can find this part of the circuit in the Keithley 236 Service Manual. Q47 is a BJT. Only the base and emitter are connected, which means it is used as a diode. I also made a…
ONLYA
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How can you block the parasitic body diode in digital CMOS I/O IC design?

I've been screwing around with IBIS models lately and came across something that left me scratching my head. First, the generic model structure for the semiconductor portions of an IBIS I/O looks like the following (taken from this article): When…
Ste Kulov
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4
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MCU working at 3.3V and RS485 driver at 5V - how does this circuit work?

I was looking for a "quick and dirty" solution in order to work with MAX487 (5V) and my ESP32 MCU. I know that Maxim integrated produces the MAX3485 and MAX3483 that are specifically designed to work with 3.3V, but I have a bunch of MAX487 (almost…
VirtApp
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