Questions tagged [high-side]

High-side refers to DC+ positive line.

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P-MOSFET - voltage on a drain pin when fully off

I'm trying to implement high side switch using P-MOSFET with NPN driver. I will drive the whole switch with AVR GPIO running at 3.3V (3.3V GPIO label). KT231B9 (it'...
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High side power switch IC drops 0.5V when loaded

I setup a circuit shown in AP2411 data sheet on a solder-less test board and connected the output to 30 ohm resistor to ground to simulate about 100mA of current. Input voltage is 3.3V from a lab ...
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DIODES' AP2411 high-side switch usage

I built circuit for DIODES' AP2411 high-side switch on a solderless test board and connected the output to 20 ohm resistor to ground. Input voltage is 3.3V from a lab power supply. The output voltage ...
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UCC27211 Gate Driver High Side Output Randomly Turns Off

I am operating a half bridge. The high side gate driver output randomly turns off. I am unable to identify why this may be happening. Attached is an image (Pink: HO, Cyan: HI, Green: LI, Blue: Vgs(LO)....
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Handle fast signal using OpAmps: ADA4891 - 2

Relating to "Handle fast signal using OpAmps: ADA4891". I added a high-side switch and a constant-current circuit. However, the hold voltage immediately drops when switching the high-side ...
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Solid state relay output connection: Is there a difference between high side and low side switch configurations?

I am planning to use this SSR chip. I decided to use the "Connection C" configuration which is given pictured in the 2nd page of the datasheet. However, there is something I don't like ...
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High-side current sensing questions: Gain formula and circuit type

What is the formula for the gain in this circuit? I can not find a good description of the operation of this high-side current measurement. Why is there a PNP transistor at the output? What is the ...
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Can you drive a P-MOSFET as a high side switch directly from a microcontroller?

I have an engineering background, but close-to-zero practical experience with discrete electronic circuit design. simulate this circuit – Schematic created using CircuitLab Regarding the above ...
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5 answers
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High side switch for high voltage Nixie tube

Short version: I am looking for a high side switch (20mA, 400V) circuit for half wave rectified mains, which I would be able to control with 5V GPUO. Long version: I am building a Nixie clock with ...
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To minimize the power loss in MOSFET of current control circuit

I am going to measure the electrical response (voltage drop vs current) of an electrical contact joint modeled as resistance 0.4 ohm in following figure. I made a prototype circuit to control the ...
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High side mosfet 12V switch from isolated 3V3 GPIO always ON

I design a High side mosfet 12V switch from isolated 3V3 GPIO on previous post, based on EL3H7-G (C) Optocoupler and STR2P3LLH6 Mosfet but it's alway ON... I don't understand why. SCHEMATIC I check ...
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Reference ground for Vgs on the source pin of an N-channel MOSFET

Hey fellas, So I'm trying to take advantage of n-channel mosfet's inherent low RdsOn, but also want a high-side configuration. I've got the following circuit here and it seems to work in this ...
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PNP high-side switching with logic reverse

I am trying to design a High side switch(24V,10A) using a PNP Transistor, the switch control signal is PNP or NPN from the PLC output. How to select the control signal type (NPN or PNP) using a ...
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High-efficiency, battery powered high-side load driver [closed]

I need to drive a resistive load with low-voltage and relatively high current, in a battery powered system. Since I need my load to be grounded, I would like to use a push-pull or high-side drive. I ...
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N-MOSFET driver for P-MOSFET high side switch

I need to create a high side switch to drive a 2.5W resistive load, which must be referenced to ground. I'm planning to use a P-MOSFET as load switch. The problem is there I have an inconstant voltage ...
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Problem Implementing high side P channel mosfet power source selector

I have build the above circuit on a breadboard and it is almost working but not quite. I've spent a number of hours on the problem to no avail. My background is not electrical but I've been building ...
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Buck converter high side switch GND

In Figure 1, I designed a synchronous buck converter using the IR2110S half bridge gate driver integration. However, when I look at the source-GND measurements of the high side MOSFETs in Figure 2, I ...
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High resistance between control ground and power ground of a gate driver IC in high-side configuration

I am working with a circuit configuration where a gate driver IC (ISO5852S) is used as a high-side gate driver and the bias supplies of this IC is coming from three isolated DC-DC converters. I intend ...
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Did I understand this diagram correctly? How do you put a load on a positive wire?

Sorry I mixed up the two diagrams, I thought both diagrams were using FETs on the right side. I am trying to turn on a 5V separate power source with a 3.3V GPIO output. I have two separate circuits, ...
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3 votes
1 answer
73 views

PNP and NPN H-Bridge - Drive PNP from opposite output

To drive the PNP transistors on an H-bridge circuit, the control voltage needs to be at least the input voltage, or a secondary stage is driving the high-side PNPs. I have come across a circuit that ...
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High side switch load isn't working as intended per datasheet. The output is always high at 12V

I bought a high side load switch from Mouser, and per the datasheet, I added 13kohms for R1, connected Pin 1 directly to GND. The input (ON/OFF) at Pin 5 is a 5V pulse with a frequency of 20Hz and the ...
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Sensing Ground Faults on a High Voltage Pulser - Coupled Inductor Issue in LTSpice

I am building a ground-fault protected High Voltage Pulser. The pulses may be as high as 500V and as narrow as 50us (20kHz). The question of how to create GFCI protection is proving to be a ...
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Voltage Doubler PWM Circuit

I have the following circuit here, a high-side N-channel MOSFET driver, with gate voltages being generated via the circuit in the middle/NE555 section. I'm wondering, how does the voltage doubler ...
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712 views

high-side circuit works?

What is the aim of 100ohm resistor between the micro-controller pin and the gate of the N-channel MOSFET?
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How to use a N-Channel MOSFET for high side switching?

According to my research, mostly N-Channel is used for low side switching and P-Channel is used for high side switching. But if I want to use N-Channel for high side switching, what are the ways and ...
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4 votes
2 answers
233 views

MOSFET High Side Switch of high DC voltage (60V), improvement and advice

This is my first post in this stack group, so please forgive me for any shortcomings of my question. I'm designing a circuit for a high side switch of around 60V DC (battery). Attached is a sketch of ...
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High side P-channel mosfet switch for BLDC driver (42V ~13A at peak)

I'm trying to design high-side switch for BLDC motor controller(42V ~13A). I understand that low-side switch is more efficient in this case, but controller schematics(bought as is) has an issue. It ...
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IC with configurable output : high-side, low-side, push-pull

As the title mentions, I need to implement a design that would require an IC that can be driven in high-side, low-side, or push-pull configuration. The main purpose for this is that I need to drive ...
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How to share a current sense pin on a single GPIO

The BTS7040 is a 2 channel High Side Switch with diagnostic feature, im planning on using 2 of the IC and i dont have extra GPIOs to spare. The way you read a fault from the BTS7040 is to select a ...
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How do I Drive High Side MOSFET in High Voltage Low Power DC-AC Unipolar Converter?

I'm working on a simple dual stage piezoelectric driver consisting of a DC-DC flyback converter (programmable from 50V to 250V) and a DC-AC half-bridge unipolar inverter. The flyback converter is ...
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528 views

MOSFET 24V high-side switch

I'm trying to control 24V solenoids using logic level inputs at 5V. The following circuit works when replacing both power loops with a single 9V battery, except that the voltage across the gate and ...
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Problem with closing high side P mosfet using B type amplifier

I am using this high side P mosfet dirving circuity: My problem is the main P mosfet doesn´t deactivate entirely. More specificly its gate is at 8,4V (with 15V vbat voltage it makes 6,6V gate - ...
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Library file error while using a Third party component( INA138)

I want to use the INA138 as a current sensing amplifier but its symbol is not available in Ltspice so I downloaded the .lib File from https://www.ti.com/lit/zip/sbom140 here. I then opened the file in ...
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Gate drive circuit for 1500VDC two switch flyback converter

I am designing two switch flyback converter for 1500VDC input solar application. I am little bit confused while selecting gate driver circuit, specially for high side gate drive. I didn't find any ...
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2 votes
4 answers
697 views

High-Side P-Channel MOSFET Won't Turn Off!

I'm using the attached circuit to control the power supply of my battery-powered product. This is the 8th version; the newest addition is Q1 which I'm using for reverse supply protection. All previous ...
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Advice for High Side Switch (High Current, Low Voltage)

I'm building a small LED driver microcontroller board and I'm looking for any advice y'all have on switching the power to it up to 9A (would take 3A, if necessary) at 3V - 5V, in a small package. I've ...
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374 views

High-side switch to disconnect battery

I have a 28V power source and a 24V power source on my device. The 28V source is permanent (internal battery) and the 24V can be disconnected. When 24V is connected, the 28V battery needs to be ...
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Smart High-Side Switch - Reverse Battery Protection Feature

I'm designing a switch for an automotive application and found this IC BTS428 that supposedly solves all my problems. Following the manual, i came with the following circuit (LATCH PUSHBUTTON). ...
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1 vote
1 answer
251 views

High side MOSFET driver with transformer

I am reading the application note " Fundamentals of MOSFET and IGBT Gate Driver Circuits" written by Texas Instrument. In order to control High Side MOSFET, the application note suggests to use this ...
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Problem with high-side current measurement

I am having strange failures in a high-side current measurement circuit that I have not yet understood. The U3 measurement chip is getting damaged and shorts out. Perhaps someone can help identify ...
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1 answer
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Detecting short circuit (max4080)

I'm using Max4080 to measure the current: simulate this circuit – Schematic created using CircuitLab The problem is it can't detect short circuit because when RS- is connected to ground, ...
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3 votes
3 answers
391 views

MOSFET High Side conducts when low side switches in H bridge circuit

I have designed an H-bridge circuit using IR4110 Mosfets. Q1 and Q4 are OFF, Q2 and Q3 are conducting. Gate of Q1 is left floating. Q2 being high side, its gate is connected to Vcc + 12V. The gate of ...
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high side switch using NMOS

I'd like to dim an ordinary 3-pin PC fan with a 3.3V-PWM at its 12V power supply pin. As I also need to measure the tachometer signal within a 3.3V logic level circuitry I'd like to switch the fan on ...
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-1 votes
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High side current sensing

I want to sense 30 amps of current using op amp in high side. I know that there are many dedicated current sensing amplifiers for this purpose. But I'd like to try it with an op amp. I have tried high ...
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2 votes
0 answers
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Humming and voltage drop on p channel Mosfet

I am designing a high side switch using P-Mosfet to drive a heat element. The Mosfet is driven by PWM from MCU, which in the test is around 40Hz, 10% duty. Here is the schematic I am testing. I am ...
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Transistor Biasing of high side switching network for PWM control

simulate this circuit – Schematic created using CircuitLab iagramI am attempting to create a high side switching circuit for a string of LEDs wired in parallel. There are multiple strings, all ...
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2 answers
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Oscillations on High Side Sensing Current Source

I designed a simple adjustable constant current source that uses high side sensing but I can't seem to figure out where the oscillations on my output are coming from. The circuit is shown in a picture ...
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1 answer
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Can I use a voltage controlled resistor to adjust high side switch current?

A number of high-side switches (e.g. the NCP380) go into constant-current mode when the programmed maximum current is reached. This is typically set with an external resistor according to the required ...
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1 vote
1 answer
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Profet Smart Highside Power Switch Output Always 'High'

I bought the Infineon Smart Highside Power Switch - PROFET BTS442E2, in order to switch a ~16V supply using a logic level PIR sensor. BTS442E2: http://www.mouser.com/ds/2/196/Infineon-BTS442E2-DS-...
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1 answer
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high side driver failure

I am having 100% failure rate trying to get this high side driver to operate. The failure happens as soon as the 5v logic signal is turned on. I have had straight shorts from VDD to GND, and I have ...
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