Questions tagged [over-voltage-protection]

Additional internal or add-on parts to a fixed voltage regulator to prevent the output voltage from exceeding a preset limit if internal voltage regulation fails. Some OVP designs include an SCR to short the output and blow a fuse, rather than risk damage to downstream hardware.

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High side reverse voltage and overvoltage protection circuit

Can someone provide an explanation why I still have a 50Vp negative waveform after the rectifier (waveform on Vch2) and after the overvoltage (output voltage) we have the same positive cycle. It's ...
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TRIAC protection for general domestic use

I am designing a smart switch for switching 220 - 240 VAC outlets for domestic use at a maximum of 16A. The load could be a washing machine, a toaster, a vacuum cleaner or any general home appliance (...
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Put an overvoltage protection between TAE box and router?

Scenario: Lightning strike in the neighboorhood, thus an overvoltage in the power grid. This happend before at my house. Now what about, if I a router is located at the neighbours power grid, that ...
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Use TRS jack as Mono + 5V power input

I'm trying to change this guitar wireless transmitter so that the audio input jack also becomes a charging/power source. The charger will be a separate box with "stereo" input socket. ...
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Input over voltage protection circuitry around RBO40 for automotive use

I have been digesting input power protection circuits for automotive use for several days now. There are a lot of snippets here and there with either complete info (no parts) or incomplete circuits (...
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Is this a correct way to divide and 'clamp' a noisy 10 V signal to 3.3 V?

I need to read a noisy 10 V Hall sensor square wave signal using an STM32 (3.3 V logic). To reduce the voltage I can use a simple resistor voltage divider, however, I'm not certain how to protect the ...
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I²C overvoltage protection fail

I have a pogo connector with +8.4 V/GND/SDA/SCL. I would like to protect my microcontroller from overvoltage (+8.4 V could potentially touch SDA/SCL). I tried this circuit: But the thing is: There is ...
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How to protect differential data lines from ESD?

How do you protect a differential signal line (like Ethernet) without a common ground from high voltage or ESD? Do you use TVS-diodes from Tx+ to Tx-? I thought of using TVS-diode arrays due to their ...
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Protect RJ45 CAN from POE

I'm trying to design a PCB with CAN Bus connection with STM32 (will be using a CAN transceiver) where we're using RJ45 for the CAN port. One of the main concern is what if the user plug in a Power ...
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Another LED Circuit Design Question - higher voltage and bigger resistor vs lower voltage and smaller resistor

I'm an avid DIY'er recycling some LEDs from a TV. It uses 50 LEDs in series, supplied by 160 V, and the PSU says 160 V @ 400 mA. So my target is to provide 3.2 V @ 400 mA in my own circuit. I would ...
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How much can the voltage range of Lithium-Ion cells be stretched?

I recently received a cheap (and probably non CE-certified product) that is capable of charging a few 18650 cells. I use it to charge recycled cells before decharging them to measure capacity. However,...
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What is an "integrated self-opening load switch" actually called?

Here is a throw-away circuit to illustrate the behaviour I'm looking for: simulate this circuit – Schematic created using CircuitLab Basically a load switch, but during an over-voltage event ...
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Self resetting crowbar circuit for over voltage protection

I'm trying to design an over voltage protection circuit that doesn't rely on custom chips (the chip shortage has shown the danger of relying on this,) so I put together a crowbar circuit like this: I ...
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How does my crowbar circuit look?

Theory of operation: op amp detects higher-than-reference voltage and triggers SCR, which remains in low-impedance state until current drops close to zero (hopefully by blowing the fuse). Main ...
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5 votes
2 answers
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Is this TL431-based overvoltage limiter circuit alright?

I have a supply rail that is 15 V nominally +/- 5%. So the highest nominal voltage is 15.75 V. Due to external fault currents of up to 200 mA, the voltage on this rail can rise anomalously. The fault ...
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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 ...
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1 answer
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ESD and overvoltage protection with varying clamping voltage

I am designing a PCB for analog multiplexing. I want to protect the signal lines against ESD and overvoltage. The voltage in the signal lines shouldn't exceed the limits of the two supply voltage ...
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Needed switch bandwidth for USB Type C D+/D- over-voltage protection

I am currently trying to add over-voltage protection to a USB C PD receptacle (with BC1.2 support.) As the SBU pins aren't used, I'd like to protect the D+/D- pins from short to VBUS. The TI reference ...
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How to add surge protection and over voltage protection for a smart switch SMPS

I am making a smart switch for toggling appliances with a 10 A relay using esp8266 as my MCU. I am using an isolated 3 W (5 V, 600 mA) SMPS. I have seen in some specifications about 2.5 kV surge ...
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Voltage clamping for 28V nominal circuit

I am using a Vishay SIP32430 load switch for a 28VDC nominal input design. The absolute maximum rating for Vin is +30VDC. My input voltage will be nominal +28VDC, but short duration, low energy ...
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2 votes
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How does this 4050 IC input protection circuit work?

While reading through the 74HC4050 datasheet I came along this input protection circuit. In order for the mosfet to turn on the gate voltage has to be more positive than the source voltage though they ...
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Protection of the pins of an electronic board against overvoltage due to a bad connection

I designed an electronic board with two inputs connected to an ADC (MCP3202), one output connected to the output of an AOP (INA105) and a 24V battery supply. My question is: is there a way to protect ...
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Which circuit is better for P-Channel MOSFET ESD and over-voltage protection?

There was damage to some P-channel MOSFETs on the PCB due to ESD and dielectric strength tests during our manufacturing. I think the original circuit design is susceptible to high voltage stress. A ...
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LTC4362 protection circuit

I found this IC that protects from Overcurrent, overvoltage and reverse polarity. I want to use it for 1A max so the datasheet's title "1.2A Overvoltage/overcurrent protector" convinced me ...
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Using a series diode to protect input with pull-up resistor

I have a switch input that I need to protect from miswiring to 12V battery power, reverse wiring to power, ESD and transients. I tried using a Zener diode circuit to handle the overvoltage: Steering ...
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LM2576 ON/OFF pin for over voltage protection

I'm trying to shut down an LM2576 regulator in the event that one of its adjusting resistors fails open. I'd like to use the ON/OFF pin on the regulator as this seemed as though it should be easy and ...
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Communication Line Protection

I intend to protect a BUS switches ICs, whose voltage on its pins cannot exceed 5.5V and 3.3V. The current cannot exceed 16mA. The circuits needs to opperate from 3.3V to 5V. But automotive ...
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Would this circuit protect from overvoltage?

The circuit below can protect from reverse polarity, but I would like to know if it can provide overvoltage protection for any voltage more than 18 volts. I have chosen a Zener diode with a breakdown ...
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Voltage/Ampere switch

I have 12 V DC solar pump. Since solar gives a variable power, I need an automatic solution to switch on the pump when the output reaches 12 V/1 A. Is there any way to do that?
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How to design a discrete flat-clamp TVS circuit

I need something similar to the Texas Instruments TVS3300 but for a higher voltage. The TVS3300 is basically a drop-in replacement for a TVS diode that clamps the voltage using an internal mosfet and ...
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"Antizener" device

A Zener diode normally starts conducting current when the voltage applied across its terminals rises over a certain threshold, called the Zener voltage. After this threshold the current keeps ...
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Triac gate biasing in crowbar circuit

This question is about whether an often-presented crowbar circuit is actually robust, or whether it is susceptible to triggering below the intended overvoltage condition. The crowbar circuit shown ...
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3 votes
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Protection against constant overvoltage from power supply

I have a project using USB VBUS as power source. Fault to protect from: a bad AC-DC 5V adapter goes haywire, or a USB form factor device with non-5V output (some laptop AC-DC with USB type C?), or ...
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Protection circuit design using crowbar

I have been working on the design of a circuit that can measure a voltage within the range of 25-40 volts. But I wanted to design a protection stage, since I will use a microcontroller for the ADC and ...
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Regulator input overvoltage protection

I am using a 2A Buck regulator from TI (https://www.ti.com/lit/ds/symlink/tps562202s.pdf?ts=1622136131438&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS562202S), with max input voltage ...
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MOV failed due to lighting or OV on power line Feeder control

we have a filed failure of our product which is feeder controller as shown in below image. It installed in metal box. we have tested our feeder stand alone at 15KV surge and it compliance with 15KV. ...
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Transformer surge protection with MOSFETS

I'm trying to come up with a good solution to protect a 48VAC circuit against power spikes from the transformer when the load is suddenly disconnected. Since I have a bunch of MOSFETs and Zeners at ...
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How to combine transient voltage TVS diode and overvoltage Zener diode for analog output?

How do I arrange my circuit so that the TVS diode can do its ESD/transient job, without being fried in the miswiring/overvoltage scenario? I have an analog 0-5V output that needs protection from ...
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3 votes
1 answer
103 views

Is input leakage current a valid way to calculate the input resistance of a digital input on a microcontroller?

I'm trying to calculate the value of a resistor to protect a digital input on a microcontroller (10Ω and 1kΩ in the image below): The microcontroller datasheet (PIC16F1718 Datasheet) doesn't specify ...
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Protecting 12 VDC against 220 V

I've made the power circuit for my project with some protections. (Fuse, Reverse Polarity, Undervoltage, working Vin is 12~24). The circuit is supplied by user. Any voltage between 0~30 is acceptable ...
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2 votes
1 answer
174 views

Use TVS and zener diode on the same circuit

In order to protect against ESD and overvoltage at a charger input, I would like to know if it is recommended to use TVS and Zener on the same circuit, if so, what would be the configuration? The ...
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-2 votes
1 answer
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Reverse the drain of a Channel - N Mosfet using a P - Channel Mosfet? [closed]

I am working on a school project which consists of converting audio signal into amplified pwm signal with a tda amplifier (raw) not a complete circuit with resistors and capacitors, then converting ...
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0 votes
1 answer
151 views

Instrumentation amplifier protection from high voltage transients with minimal signal degradation

I am looking to protect an INA849 at 2000 or more gain from high voltages of 30 volts AC at various frequencies. Currently I am using an analog switch IC as the only time the high voltages are sent ...
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1 answer
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Circuit Protection to the current circuit

I have a basic circuit that uses 555 timer to generate PWM signal and the PWM signal turns the high side switch, SI1865DDL, on and off at certain frequency and duty cycle. The output from the high ...
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Complete summary of all protection in a circuit?

this is what I have learned and I wanted to know if you can add more to my current understanding in protection. For short circuit (which applies both to overvoltage and overcurrent): Use a fuse first ...
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Choosing the right Over-Voltage protection circuit

TLDR : Ideal supply voltage of a device is 12v DC (labeled near jack). User may mistakenly provide anything from 3 to 24 DC (or maybe 220v AC). how to protect the circuit against Over-Voltage ? how to ...
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1 answer
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Does a TVS diode provide adequate protection for an LCD screen powered from a car 12V outlet?

I fitted an LCD screen in my car and I want to power it, along with other devices, directly from the car's battery. The other devices are specifically designed for automotive use, but the screen, a 10....
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1 answer
217 views

Protection circuit with polyfuse and zener

I'm designing a protection circuit with polyfuse and zener for DC 5v input. I have try it fisically but the polyfuse never trigger because the zener burns before when I plug 6-12V to the input. My ...
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Power supply protection

I'm trying to create a power supply protection (overvoltage, undervoltage, reverse polarity) for a ±33 V, 7 mA power supply for an op-amp. The opamp would be powered by a lab supply in theory. So the ...
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ADC Clamping Rrotection Circuit with Dual serial Diodes - Formula proof

I am trying to undestand and calculate why in the first circuit we measure 5.7Volt (if forward noltage diode is 0.7Volt) and not 12V. I used the Superposition Theorem which first I replaced the Vcc ...
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