Questions tagged [p-channel]
The p-channel tag has no usage guidance.
61
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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 &...
0
votes
0
answers
45
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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 ...
- 67
2
votes
2
answers
250
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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 ...
- 155
1
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2
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270
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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 ...
- 50
0
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3
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44
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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 ...
1
vote
0
answers
79
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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 ...
- 117
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4
answers
904
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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 ...
- 147
1
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1
answer
117
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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 ...
- 25
0
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1
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72
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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 ...
- 411
3
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2
answers
316
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(−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 ...
- 501
1
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3
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420
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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 ...
- 11
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3
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673
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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 ...
- 51
3
votes
1
answer
127
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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 ...
- 33
2
votes
1
answer
160
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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 ...
- 153
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2
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121
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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 ...
- 411
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2
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216
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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 ...
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1
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0
answers
114
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RPI Pico charging mosfet schematic
As per the recomendation of RP, 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 as follows. I ...
- 163
1
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0
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112
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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 :
...
- 411
20
votes
2
answers
1k
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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 ...
- 827
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2
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149
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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 ...
3
votes
1
answer
188
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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 ...
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0
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88
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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 ...
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2
votes
2
answers
171
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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 ...
- 23
1
vote
2
answers
644
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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 ...
- 319
0
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1
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119
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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 ...
-2
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1
answer
88
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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 ...
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5
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1
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520
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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 ...
- 525
1
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3
answers
102
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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 ...
- 1,865
0
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0
answers
153
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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 ...
- 1
2
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2
answers
2k
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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.
- 51
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3
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675
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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 ...
- 113
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0
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320
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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 ...
1
vote
1
answer
281
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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 ...
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1
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302
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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. <...
- 275
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5
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5k
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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 ...
- 141
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1
answer
99
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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 ...
- 51
0
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1
answer
169
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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 ...
- 301
5
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2
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6k
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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 ...
- 97
-1
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1
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143
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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 ...
0
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2
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552
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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 ...
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3
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1
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392
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How to operate a P-channel MOSFET with an LM358 op-amp to bypass a DC-DC power supply with 5-24 VDC in and 5 V out
I am trying to create a PCB that can operate on 5, 12, or 24 VDC. The PCB will need a 5 V rail for the digital signal to the LED lights and a 3.3 V rail for the MCU.
I would like to make a cost-...
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1
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275
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Delay circuit after power on for ESP32 application
I'm using the ESP32 with a sensor connected to UART0 and I want to suppress the first stage bootloader log, since it can lead to delayed response of the sensor later on.
Therefore I want to pull the ...
- 171
1
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3
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237
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Does the Zener diode in this schematic need a current limiting resistor?
This is a fairly generic P-Channel MOSFET driver. The supply voltage is 12 - 48 V. The Zener used is a BZX84-C12. Would this Zener diode need a current limiting resistor of, say, 1 kiloohm between <...
- 1,320
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0
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413
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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 ...
- 143
1
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1
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783
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RDS measurement on P-Channel MOSFET
I want to measure the Rds-ON of a P-Channel MOSFET and I have setup the test circuit as follows:
I keep the source at constant +10V and vary the step the gate voltage up in the increments of 1V. Then ...
- 65
3
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0
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128
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High-side mosfet switch placement
this is a power circuit I'm trying to complete:
the button at top turns the curcuit on, supplying VCC to mcu, and the MCU will output a high signal to a pin (marked in pink) which turns the N-MOSFET ...
- 198
2
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1
answer
124
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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 ...
- 51
1
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2
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148
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basic p-type mosfet circuit, breaks mosfet?
So I've made this basic circuit to drive Vout between ~0V and ~1.65V.
The default state should be ~0V, hence I use a p-type mosfet:
https://docs.rs-online.com/d95a/0900766b800ae907.pdf
Now, for some ...
- 324
2
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3
answers
717
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How is current flowing through this P-channel MOSFET?
I am probably being stupid and should probably go to bed but how is current flowing in this circuit below?
From my understanding, a P-channel MOSFET allows current to flow when its gate terminal is ...
- 83
0
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1
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84
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what driver chip do i need for a irf4905 p-channel mosfet [closed]
I'm trying to figure out what chips I need to run my irf4905. the mosfets will need to be running 5 amps at 24 volts using pwm to Varey the watts. if anyone has done anything with this mosfet an knows ...
