Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [p-channel]

60 questions
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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 reversed - as if current was flowing from…
InBedded16
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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 schematic, let's say I have a P-MOSFET (type SiA441DJ),…
Oliver Richter
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3 answers

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 want the LED not to flicker with any grade of…
Seb Wilson
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1 answer

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 protection. If so, then why are MOSFETs better…
dharmikP
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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 body diode in the MOSFET, but still I do not quite…
moci
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4
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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 there will be a signal inverter SN74LVC2G04 for…
Maxim
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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 the gate and source is 16 V to prevent exceeding…
pbandjazz
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2 answers

Solution for how to drive a P-Channel MOSFET when Gate/Source voltage is too low?

I have used this forum to lookup solutions and suggestions from time to time but this is my first ever post! There are many great P and N-Channel MOSFET Questions and Answers in here, but I cannot find a solution to what I am asking. I have needed…
MWestberg
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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 to −40 V. I predict that the system consumes a…
Electronx
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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 MOSFETs available anymore. My question: What is the…
HannesW
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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 low in my 3.3 V TTL (with a single part). For…
Nick Bolton
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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 bus-powered over USB-C, which I believe means I…
Harry Brooke
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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-effective way to accept VIN as 5 V and automatically…
Jimmy James
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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 on, and the P-MOSFET on as well. (right?) when…
Elementronics
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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 programmer reset the module? (The MOSFET has Rds…
alsaleem
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