Questions tagged [low-side]
The low-side tag has no usage guidance.
50 questions
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Low Side Switching a PC
I made a PCB that takes 12V power in and passes it to the output connector, except the GND connection on the output has a low-side switching circuit through an N-channel MOSFET. The gate of the MOSFET ...
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High Current, High Voltage DC Load Switch using NMOSFETs
I am designing a Power Monitoring and Protection board that is going to sit in between a 5-Series (~70V) Lead Acid Battery and a load. This board has a Energy Monitoring IC from TI - INA237AQDGSRQ1 ...
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MOSFET switching with PWM
I have a question about MOSFET switching. I have a 126V voltage source and I want to drive it with a PWM signal. There will be a buck converter at the output of this MOSFET.
What is wrong with this ...
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Low-Side Driver Not Sourcing Current from Load to GND
I have a circuit with an electronic load in parallel with an optocoupler and a low-side N-channel MOSFET connected to the circuit. The low-side N-channel MOSFET driver is supposed to source current ...
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Control slew rate with low side PWM power transistors
In a special project I'm trying to do PWM current control of a electromagnet like application.
This project is special because it has to pass very strict EMI tests (<30Mhz radiated emissions).
...
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IRF630N MOSFET burns after a couple of times in use [closed]
I made a simple circuit using an IRF630N to drive my loud buzzer. The Arduino code is very simple, just high and low on the pin for a fraction of time. Following is the schematic of the circuit
After ...
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Gate driver circuit design for High-side and Low-side
I am designing integrated DC-DC converter with multiple output. As I am new to Analog design, I am trying to figure out what type of circuit topology is to be used for high-side and low-side switches. ...
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NMOS as a low side switch
I am trying to use an NMOS(2N7000BU) to "turn off" the LM350 voltage regulator. I have an OR gate going into the gate of the mosfet, so either input will turn it off. The hope was to ground ...
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switching multiple supply voltages on same low-side darlington array IC
Say I have an MCU switching a couple SSRs using the ubiquitous ULN2803 at 5V on the "common" pin, but I'd like to switch a 12V mechanical relay with the same chip as well. Checking the ...
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Power control of IC chips with N-Channel MOSFET
I'm building a battery-based wireless weather monitor for hobby project.
for longer battery life, I want to control the power of each subsystem separately.
Let's take a NRF24 modem for example: ...
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Can you use a diode to cancel the body diode of a MOSFET?
From what I understand, MOSFETs inherently have a diode between the source and drain known as a body diode. If I were to use an nMOSFET as a low side switch, would it be bad to have a diode between ...
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ULN2003 low-side switch electrical characteristics
ULN2003A
So I'm currently exploring low side switches. I started off with an NMOS transistor array IC (Open drain), to develop a better understanding I've tried to understand the Darlington transistor ...
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Low-side switch TPL7407LA-Q1 [closed]
I have some questions regarding the TPL7407LA-Q1 low-side switch.
As far as I know, this IC is typically coupled with GPIO pins on a microcontroller, so supply voltages are limited. On the product ...
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How to manage MOSFET spikes in low side switch switch
I've seen lots of questions here about various spikes/overshoots/transients when using MOSFETs but when I try to apply the solutions to my circuit I can't seem to apply them in a way that makes much ...
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Removing the effects of Parasitic Inductance in current sense resistor – Low side current sensing
We are evaluating MIC21LV32 from microchip in one of our applications.
For the current sensing we have used 3 mΩ sense resistor (1206, 1 %, 1 W), as these sense resistors have higher ESL+ parasitic ...
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Gate source voltage of half bridge with bootstrap capacitor incorrect when measured
I have a gate driver circuit (Bootstrap capacitor for high side) as in the given diagram.
I measured the Vgs for high and low side as shown in the figure below. I get the wrong voltage level for the ...
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Is there an alternative to gate drivers like TC4428 or MIC4426 in LTspice?
I need a dual low-side gate driver but there are just single output N channel drivers in LTspice.
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High side current sensing amplifier placed on low side. Possible?
I am trying to build a custom 12 volt battery current sensor for my car as a little hobby project. I want to place a shunt on the negative side of the battery, and get the measurements from there and ...
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3-phase inverter low side current sense
The setup
I'm currently doing some experimentation with 3-phase inverters for BLDC motors and current sense. I have at hand this board featuring:
IR2103 MOSFET driver. LIN# inputs are connected to ...
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Low side driver and flyback diode
I wanted to control electric door lock (12V, 1.5A peak, unlocking time < 200ms) with Self-Protected Low Side Driver like NCV8412 (https://hr.mouser.com/datasheet/2/308/1/NCV8412_D-2317556.pdf). One ...
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Low-side current sensing for FOC (synchronisation)
I am working on the implementation of an FOC controller for a BLDC motor and I am confused about the synchronisation I should perform between ADCs and PWM.
The setup implements 3 leg low-side ...
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Why is there a Schottky diode connected to the low-side switch
I am trying to understand the reason for having a Schottky diode for protection in a buck switch by reading here.
To summarize, I can understand why two the switches should not be turned on at the ...
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Relay does not switch off
I have what I thought was a simple relay circuit but the relay is always on.
This is the part of the project that is not working
Q5 never switches off.
To simplify it further I removed the relay and ...
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EMI and reliability considerations for low-frequency, low-voltage DC load drive
In my application I need to drive a 240W pure-resistive load with a nominal voltage of 24V.
The input is a standard 280W AC-DC external power adapter, the Meanwell GST280A24.
The load switch is ...
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EMI voltage ripple issue for low side NFET
Under some user suggestion, I decided to drive my 10-ohm load heater using a low side NFET. I put a 1k resistor (R1) at the NFET gate to reduce ringing. I got, before placing the resistor, a very bad ...
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Calculate temperature for low side switches?
I would like to know how to calculate the temperature (to see if I am still in a working range) for a low side switch. Hope you can help me there.
I need to control 10 valves(12/24V - 500mA max. ea.) -...
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Problems with low-side MOSFET in 12V LED dimming switch
I'm pretty new to electrics/electronics. I'm sorry if I make dumb questions, and thank you for your time.
I wanted to control my LED strip shipped from Ebay, which works well with 12V 2A DC adapter. ...
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Low-Side LED PWM - Constantly On
As a now-professional EE, I'm slightly embarrassed to be asking what I feel like is a simple question. But I'm stumped and google isn't giving me good answers.
I'm trying to PWM a string of LEDs via a ...
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Verifying electric brake current with opto-isolated feedback
I would like to find a way to sense (or detect) current through an opto-coupler.
This opto is used to power an electromagnetic brake, but depending on the type of brake the current through it can ...
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Back to back N-MOSFET on low side
I would like to disconnect the current in the system with a battery (using N-MOSFET in a back to back configuration).
I would like the circuit to be on the low side and without a driver.
At this point,...
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Define the purpose of these components in the operation of this low side driver
I am trying to understand the operation of the following low side driver circuit I found in a schematic of an old pinball machine (redrawn for clarity):
L1 is a Solenoid and Q1 is a Darlington BJT (...
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BLDC low-side gate oscilations
I am developing the BLDC motor controller board and I have problems with low-side gate driving. I am using MC33035 BLDC motor controller. PWM for speed control is fed into low-side MOSFETs. High-side ...
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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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In this low side switching schematic does the 10k resistor play any role?
I've been given this schematic to review it (I'm working on a formula student team.) It is used for cutting off the power to a motor through a N-mosfet (NCV8402A). The 12V are being supplied through ...
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How to drive MOSFET switches in a cascaded hybrid modular multilevel converter using a half-bridge driver "IR2103S"
I am trying to drive the MOSFET switches in a cascaded hybrid modular multi-level converter as shown in Fig. 1. Fig. 2 is used here to simplify the circuit and to present the problem (let's focus on ...
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How to make a HIGH pin on ESP8266 go LOW when device is turned off using a low side switch?
I ran into this issue while working with WeMos D1 Mini and Adafruit's timer board.
I had an N-channel MOSFET that was driven by the timer's DRIVE pin. When ESP was done doing its thing it would ...
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Low-side switch MOSFET cannot deliver full voltage
I have designed a portable lens heater prototype. Using:
18650 Li-ion battery
Arduino ProMicro (3.3V , 8MHz) by adafruit (https://www.sparkfun.com/products/12587)
Push button switch
PMV16XN N-channel ...
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Low-side current sensing, raising the ground?
One of the main reasons why we don't use low-side current sensing for PSUs is that we want the ground to be, 'ground'. adding a shunt resistor will rise the ground slightly higher.
In real world ...
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Mosfet Driver - High Side Output Problem
I've been trying to make a 3 phase inverter to drive a BLDC motor.
Mosfets : IRF3205
Driver : IR2101
Supply voltage for FETs and drivers : 12V
BLDC : https://media.digikey.com/pdf/Data%20Sheets/...
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Why does the PWM signals amplitude drop once connected to low-side n-mosfet switch?
I am applying a 3.3 V pwm signal to a circuit similar to the following (Credit: Olin Lathrop):
I am using an IRLR024N N-MOSFET, which switches if i connect the gate to the 3V3 pin of my ...
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How to isolate a RLC circuit with MOSFET switches?
I'd like to isolate, with high-side and low-side switches, a RLC circuit after the inductor has been energized with a current of 2-3A from a 12V source (see sketch).
When the RLC circuit is isolated ...
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Measuring pwm output from low side FET with oscilloscope
I have a n channel MOSFET controlling a high current LED panel. The FET is driven by a FET driver, which is itself driven by a MCU pin. I am using PWM to control the LED brightness.
I want to double ...
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HO defaults "On" on high side/low side driver
I have an application where I need to drive 2 piezoactuators in a push-pull arrangement (voltage 180deg out of phase with each other) where the charge/discharge time is about 50 microseconds and the ...
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What is a (side) current alarm?
On the technical sheet of a motor controller integrating two BTS7960B (picture below), the description of the 8 PINs on the board is as follows:
RPWM: Forward level or PWM signal input, active HIGH
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Can I drive a Low-Side MOSFET from a High-Side Driver?
I'm working on a power electronics project where it involves driving 4 different MOSFETs, (3 HighSide and 1 LowSide). Rather than using a different IC for the LowSide driver, I am thinking about using ...
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Current sense amplifier for high voltage (100-150V) low current (20 mA) application [closed]
I have an application where I need to measure the current on a relatively high voltage rail. The problem is that the current on the rail is quite low, only about 20 mA.
Because of the high voltage, ...
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H-bridge low side current sensing: Current signal with oscillation why?
my problem is the following: I am using two DRV8842 H-bridge ICs to control 2 different brushed DC motors, my intention is to use a PI controller for the current loop. The schematic looks like this:
...
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IR2133 Bridge driver not working as expected
I want to use the IR2133 to drive a mosfet rectifier. I have setup as in the circuit below
The probelm is (take first high side fet as example) that the signal that appears on HO1 is exactly the same ...
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Low-Side Switch MOSFET Drain Voltage Drop in OFF state?
I'm trying to replace a normally open switch with a low-side switch mosfet. The drain of the mosfet is connected to an input pin of a non-modifiable 3.3V MCU.
Prior to my changes to the setup the ...
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high side vs low side current sensing in isolated bench power supplies, does it matter?
I'm trying to make a couple of mains isolated, transformer based, bench power supplies. Considering that the current sense resistor will be in the PSU box and external loads will not have access to ...
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