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P channel MOSFET for PWM Peltier control (Arduino)

I want to control the power of a Peltier device using a MOSFET PWM controlled by an Arduino. In order to "smooth" the power going to the Peltier, I want to add a capacitor in parallel. The &...
user3256556's user avatar
0 votes
3 answers
118 views

Driving a P-channel MOSFET with high voltage input

I designed a buck converter as an MPPT charger using high side switching. It seems the signal on the gate of the MOSFET good. If a solar panel with low voltage like solar MPPT 18volt there isn't a ...
freeman3020's user avatar
0 votes
2 answers
133 views

Connecting circuit to ground when control voltage is 0 V with a P-channel MOSFET

I'm trying to control a Playstation 2 dance game controller with an external voltage using P-channel MOSFETs and I think I am out of my element here as I can't seem to figure out why this isn't ...
SenPi's user avatar
  • 37
2 votes
4 answers
215 views

P-Channel MOSFET circuit

I have the circuit below on a PCB. I am trying to provide 48V across R5 at power-on, then after a delay, disconnect R5 from the input power. I have three questions regarding this circuit. Question 1: ...
HV16's user avatar
  • 345
5 votes
2 answers
246 views

Has anyone ever obtained a P-Channel Depletion mode power mosfet? [closed]

I cannot find any P-Channel Depletion mode mosfets at any supplier. I see this question from 10+ years ago: Where are the depletion PMOS transistors? But has ANYONE been able to source a P-Channel ...
NULL pointer's user avatar
2 votes
1 answer
75 views

How do I switch on an LED strip when the control signal is pulled low?

So I'm basically trying to take a control signal from one device (5 V), and use it to control a 12 V LED strip (1 A or more). The control device is an electronic dance pad (StepManiaX Stage,or Dance ...
SenPi's user avatar
  • 37
0 votes
3 answers
131 views

Pulling pin low through PNP BJT?

I'm using a battery charger/buck regulator IC that turns on if the pin named "shphld" is momentarily pulled low, and turns off if the pin named "shpact" is momentarily pulled high. ...
FloydPage's user avatar
0 votes
0 answers
64 views

Will the gate driver circuit of MOSFET work?

I have implemented this circuit in the hardware. The desired pulse output across 2 Ω is 28 V output, minimum 10 A output current with 100 kHz frequency and 10% duty cycle. The drain pulse is not ...
Sahasra Vaiishnavi's user avatar
0 votes
0 answers
98 views

Wireless charger reverse engineering

I am trying to figure out how to design an H-bridge for a wireless charger. And I thought that reverse engineering an off-the-shelf one might give me some clues. I might have made numerous mistakes ...
shklj's user avatar
  • 27
1 vote
2 answers
188 views

12v / 24v P-Channel MOSFET Driver Issues

I'm building an open source hardware board for "home automation" / digital switching of DC loads that is mostly focused on boats / marine applications. To give some context, here are some of ...
hoeken's user avatar
  • 13
1 vote
3 answers
81 views

Low side P-FET usage is opposite of expected, what did I do wrong?

I'm working on a circuit that should close a reed relay (normally open) when TI/COUT is low and open said relay when TI/COUT is high (6V). I'm using a P-FET low side transistor to ground the relay &...
Sveinung Kval Bakken's user avatar
0 votes
0 answers
102 views

P-channel MOSFET switch is broken in high voltage

i want to use a mosfet switch 30V voltage the motor operates when the temperature is high before this circuit i changed R9, R10 R9 -> 4K7 R10 -> 680 and MOSFET was broken so i changed R9, R10 ...
KimJiHoon's user avatar
3 votes
2 answers
332 views

Can I use a P-channel MOSFET to switch a lower voltage?

I have a BLE module. The reset is pulled up to 1.8V. The IOVDD is 3.3V. I need to use a programmer that can reset the module but the programmer is 3.3V. Is it ok to use the circuit below to make the ...
alsaleem's user avatar
  • 165
1 vote
2 answers
1k views

Driving a 12-to-24 V P-channel MOSFET with TTL

I'd like to control up to 16 motorized valves with an ESP32. I'm using 74HCT595 shift registers (5 V outputs, 3.3 V input logic) to drive 12 V relays via NPN transistors. But the relays are pretty ...
Ethan Arnold's user avatar
0 votes
3 answers
54 views

IRLML9301PBF as high side switching for 5 V, 2 A load from a 3.3 V uC?

Circuit: simulate this circuit – Schematic created using CircuitLab I would like to cut off the power to my APA102-LED-strip during uC sleep - as the standby current of these strips is relative ...
Stefan Krüger s-light's user avatar
1 vote
0 answers
90 views

P-Channel MOSFET Stays Conductive When Above 11 V

I recently assembled a custom PCB which includes a P-channel MOSFET circuit to switch on and off 12 V loads. It is able to switch up to 11 V, but once the input voltage is above that the output stays ...
Vera Fodor's user avatar
4 votes
4 answers
2k views

Logic-level, high-side, P-channel MOSFET switch

I want to use a MOSFET for high-side switching of the DRV425 fluxgate as it has no enable pin, and has quite a high power consumption (150 mW @ 5V -> 30 mA): Before the P-channel MOSFET WTM2301 ...
Maxim's user avatar
  • 167
1 vote
1 answer
131 views

Is my circuit ok, using an N channel MOSFET to switch a P channel MOSFET for a high side switch

I'm using an CP361 voltage protection to ensure 5 V, this switches an N channel MOSFET which then creates a link to ground for the P channel MOSFET. The link to ground turns on the P channel MOSFET ...
gigado's user avatar
  • 25
0 votes
1 answer
100 views

GPIO directly driving a P-channel: voltage too high?

I've decided to simplify my previous "solid-state switch" that has to switch 5A @ 60V. Instead of using an N-channel MOSFET plus a gate driver (which has to have a charge pump in order to ...
VoltsAndNuts's user avatar
3 votes
2 answers
379 views

(−40)–(40)V P-channel MOSFET based reverse polarity protection

I'm building a P-MOS based reverse polarity protection circuit. The input requirements are as follows. It needs to carry 8–40 V input voltage to the output and it needs reverse polarity protection up ...
Electronx's user avatar
  • 756
1 vote
3 answers
2k views

P-Channel MOSFET used as a load switch, practical doubt about Vgs

UPDATE AT THE BOTTOM in a battery powered project with high current I'm using a P MOSFET as load switch in place of a mechanical switch to prevent inrush current and consequent spark on the switch ...
Fabio's user avatar
  • 11
5 votes
3 answers
1k views

Will this high-frequency PWM LED driver and MOSFET circuit work OK?

I am taking a PWM input (0-12 V) from a TLC59711 (driven by SPI from a Raspberry Pi) and I want to drive a P-channel MOSFET. It is driving a 12 V, 40 W LED. I want to switch at high frequencies, as I ...
Seb Wilson's user avatar
3 votes
1 answer
311 views

Alternative to depletion mode P-channel MOSFET based voltage limiter?

I find this voltage limiter circuit very simple and useful: simulate this circuit – Schematic created using CircuitLab To my surprise, neither Mouser nor Digikey have P-Channel Depletion Mode ...
HannesW's user avatar
  • 33
2 votes
1 answer
275 views

P-channel MOSFET load switch drawing more current than expected

I am testing this circuit on a PCB that I've built and I'm experiencing a 1 mA current draw when enabling it. The aim is to turn on/off a transceiver that needs 3 V and max current draw of around 500 ...
Luke Galea's user avatar
0 votes
2 answers
214 views

Ideal diode P-channel + matched transistor

I've eventually replicated the ideal diode as described in this schematic using a matched transistor pair. It seemed to be working fine at first, but my VDS is around 6-700 mV at only 8 A which is ...
VoltsAndNuts's user avatar
4 votes
2 answers
228 views

P-channel FET won't turn off from micro

I'm having an issue with what I think is a standard high-side PWM LED dimmer circuit. It uses a P-channel FET ATP304-TL-H and gets an input voltage of anywhere from 9 V to 16 V. The Zener diode across ...
pbandjazz's user avatar
  • 337
2 votes
0 answers
253 views

Raspberry Pi Pico charging MOSFET schematic

As per the recommendation of Raspberry Pi Pico, using a P-channel enhancement type MOSFET (DMG2305UX) to switch the the power to VSYS pin isolating the battery when VBUS is available. The schematic is ...
Suresh Kumar's user avatar
1 vote
0 answers
185 views

P-channel MOSFET + op-amp ideal diode

I'm replicating the ideal diode circuit from Crutschow. I'm using the op-amp flavor in order to get a very low quiescent current. The P-channel MOSFET will be a NTMFS002P03P8ZT1G. My questions are : ...
VoltsAndNuts's user avatar
20 votes
2 answers
2k views

Reverse polarity protection circuits all seem wrong

I've been looking into reverse polarity protection and come across a lot of resources that recommend using a P-channel MOSFET with a Zener diode. Every single one of these circuits shows the MOSFET ...
InBedded16's user avatar
0 votes
2 answers
346 views

P-channel MOSFET circuit schematic [closed]

I am using a P-channel MOSFET as a switch on my project, schematic below: As soon as I power my board the LED is powered on, indicating the MOSFET is working, but it was supposed to be turned off ...
rogeriomoraes_'s user avatar
3 votes
1 answer
223 views

How do I drive a 10 V high side PFET with only 3.3 V logic?

I'm trying to use a high side PFET to drive a load (50 Ω below for example, but actual case is a 200 mA motor). I know that I can use a low side NFET but that is active high, and I want to use active ...
Nick Bolton's user avatar
  • 2,113
0 votes
0 answers
109 views

Shifting voltage levels to drive high-side P-channel MOSFET

I have an H-bridge with P-channel MOSFETs for the high side and N-channel MOSFETs for the low side. I am driving a 32 V source. The source is first divided by two capacitors in order to correct the ...
lidorov19's user avatar
2 votes
2 answers
187 views

P-CH MOSFET high-side switch not turning on

The datasheet of SE2305Q is HERE I have an LCD screen that comes with a backlit_power pin which requires 3.3 V to light up. It draws quite some current, and I don't think it is good practice to ...
Simeng Fu's user avatar
1 vote
2 answers
1k views

High-side MOSFET switch

I would like to switch 3 separate 60 V, 20 A fused loads on/off high side from an ATMEGA328P. It needs to be switched high side for 2 reasons, I don't want live to have the potential to short to ...
Jay Dee's user avatar
  • 339
0 votes
1 answer
265 views

Use of MOSFET or BJT

I'm trying to fix this water dispensing pump, and got stuck in between MOSFET vs transistor working principles. For some reason the MOSFET stopped working and the pump as well. Now I am trying to ...
Mohammed Azeem's user avatar
-2 votes
1 answer
118 views

3 P-channel MOSFETs in parallel. Massive 12V supply, 10uF capacitor from gate to source. All 3 FETs sometimes fail open simultaneously on power up

My customer is using three SQD45P03-12_GE3 P-channel MOSFETs in parallel. There is a massive 12 V supply with a 10 uF capacitor from gate to source. There's a single bias resistor. All 3 FETs ...
Ken's user avatar
  • 1
5 votes
1 answer
611 views

What is the use of a P-channel FET on a power line?

I was going through a schematic of one controller. I found this circuit for the VIN pin: What is the DMG2305UX (Q1) P-channel MOSFET used for? I have read that MOSFETs are used for reverse polarity ...
dharmikP's user avatar
  • 525
1 vote
3 answers
122 views

P channel to get input signal state

I want to detect when a ground input is connected to my circuit. My specs are, that when there is no ground signal then 0V needs to go to my microcontroller. When I have ground connected to my circuit ...
JoeyB's user avatar
  • 2,389
0 votes
0 answers
182 views

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 ...
RJS's user avatar
  • 1
2 votes
2 answers
2k views

What is the purpose of the capacitor (C97) in between the gate and drain of the p-channel MOSFET in this power control circuit?

I can't figure out what purpose the capacitor serves.
kh.tf's user avatar
  • 51
3 votes
3 answers
791 views

Would this inrush current circuit work in practice?

I am building a USB hub circuit, which, because of the 120uF capacitance requirements on upstream USB ports, means that I need to charge those large capacitors in my circuit. However, my hub will be ...
Harry Brooke's user avatar
0 votes
0 answers
391 views

P-MOSFET driver

I need to drive a P-channel MOSFET from an output of a 74HC595 shift register which is controlled by an ESP32. The MOSFET load will be a high power LED. Once the register is latched the outputs will ...
Petrescu Cristian's user avatar
1 vote
1 answer
423 views

MOSFET PWM issue

I want to dim an LED and have connected a P-channel MOSFET to switch the high side. I added a N-channel MOSFET as a driver. The schematic is attached below. I'm applying a PWM sine signal from an ...
lazerlini's user avatar
1 vote
1 answer
415 views

P-Channel MOSFET power selector question

I've seen this circuit used in several ESP32 designs (e.g. the Sparkfun ESP32 Thing) and in an answer on this site that allows a device to be powered by either 5V from a USB connection or a battery. <...
par's user avatar
  • 275
8 votes
5 answers
10k views

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 ...
Oliver Richter's user avatar
0 votes
1 answer
134 views

Power consumption for reverse polarity protection using p-channel MOSFET

I'm looking for a way to implement reverse polarity protection for a circuit that runs from a CR2032 battery (The operating voltage of the circuit is from 1.8 V to 3.2 V). I'm considering using the ...
Blims's user avatar
  • 51
0 votes
1 answer
217 views

How to use a MOSFET to switch up to its Vds rated specs (e.g. 100 or 150 V)?

So I'm still learning (old dusty ETE degree I finally got around to making use of lately), so be nice please. I get a ton of snark sometimes when I post a question on here. But then there's always one ...
VanGogh66's user avatar
  • 301
5 votes
2 answers
10k views

Reverse Polarity Voltage Protection Using P-MOSFET

Could you please help me understand why in a reverse polarity circuit with P channel MOSFET Source of the MOSFET is connected to the LOAD and DRAIN to the power supply? I understand the concept of a ...
moci's user avatar
  • 97
-1 votes
1 answer
197 views

What is a through-hole equivalent to the irlml6401 P-channel MOSFET [closed]

Newbie here. My hobby project uses the irlml6401 P-channel MOSFET but I'm finding it impossible to solder the surface-mount package it comes in because I have trembly hands (gets worse as I try to be ...
Mark Highton Ridley's user avatar
0 votes
2 answers
791 views

How to calculate base voltage and current for NPN transistor required to drive a P-channel MOSFET gate

I'd like to use a P-channel MOSFET as a on/off switch. I can't pull the gate down directly from my controller because the voltage of the load is 12v, thus I have to use another transistor, as far as I ...
php_nub_qq's user avatar