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I'm trying to use a MOSFET, an N-channel (specifically specifically this oneIRLB8721PbF), with a gate controlled by an AVR to power on/off a Raspberry PiRaspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V+5 V rail).

When I measure the current the raspberry pi'sRaspberry Pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v5 V from my power supply is directly to the raspberry piRaspberry Pi GPIO 5v5 V.

As a kind of experiment control: I just power the raspberry piRaspberry Pi directly from my power supply 5v5 V/Groundground. I measure the raspberry picurrent the Raspberry Pi draws through 5v5 V with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A45 A) and settles at about 0.35 A35 A.

However, when I measure how much current the raspberry piRaspberry Pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry piRaspberry Pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V10 V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A60 A, and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfetMOSFET.

Here's a diagram of the circuit (please note: I can re-create this situation without the micromicrocontroller at all, and just with the raspberry piRaspberry Pi + bench power + mosfetMOSFET, as diagramed). Note that in this representation the raspi gpioRaspberry Pi GPIO connection is simplified and in this diagram pin 1 on the jumper = 5v5 V, and pin 2 = GND.

enter image description hereEnter image description here


Update: TurnsIt turns out the voltage drop on the MOSFET is enough to give the Raspberry Pi fits. A friend of mine pointed it out in the data sheet, and here's a screen capture of the exact graph that shows where approximately 0.15V15 V are dropped, which can be measured on source and drain (as pointed out early on! great eyes guys, I really appreciate). I have decided to instead use a relay.

enter image description hereEnter image description here

I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here


Update: Turns out the voltage drop on the MOSFET is enough to give the Raspberry Pi fits. A friend of mine pointed it out in the data sheet, and here's a screen capture of the exact graph that shows where approximately .15V are dropped, which can be measured on source and drain (as pointed out early on! great eyes guys, I really appreciate). I have decided to instead use a relay.

enter image description here

I'm trying to use a MOSFET, an N-channel (specifically IRLB8721PbF), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5 V rail).

When I measure the Raspberry Pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5 V from my power supply is directly to the Raspberry Pi GPIO 5 V.

As a kind of experiment control: I just power the Raspberry Pi directly from my power supply 5 V/ground. I measure the current the Raspberry Pi draws through 5 V with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A.

However, when I measure how much current the Raspberry Pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the Raspberry Pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10 V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60 A, and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the MOSFET.

Here's a diagram of the circuit (please note: I can re-create this situation without the microcontroller at all, and just with the Raspberry Pi + bench power + MOSFET, as diagramed). Note that in this representation the Raspberry Pi GPIO connection is simplified and in this diagram pin 1 on the jumper = 5 V, and pin 2 = GND.

Enter image description here


Update: It turns out the voltage drop on the MOSFET is enough to give the Raspberry Pi fits. A friend of mine pointed it out in the data sheet, and here's a screen capture of the exact graph that shows where approximately 0.15 V are dropped, which can be measured on source and drain (as pointed out early on! great eyes guys, I really appreciate). I have decided to instead use a relay.

Enter image description here

4 Added update to go along with answer, also screen capture of datasheet to show exact parameter.
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I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here


Update: Turns out the voltage drop on the MOSFET is enough to give the Raspberry Pi fits. A friend of mine pointed it out in the data sheet, and here's a screen capture of the exact graph that shows where approximately .15V are dropped, which can be measured on source and drain (as pointed out early on! great eyes guys, I really appreciate). I have decided to instead use a relay.

enter image description here

I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here

I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here


Update: Turns out the voltage drop on the MOSFET is enough to give the Raspberry Pi fits. A friend of mine pointed it out in the data sheet, and here's a screen capture of the exact graph that shows where approximately .15V are dropped, which can be measured on source and drain (as pointed out early on! great eyes guys, I really appreciate). I have decided to instead use a relay.

enter image description here

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3 Added schematic, note about schematic
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I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here

I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

I'm trying to use a MOSFET, an N-channel (specifically this one), with a gate controlled by an AVR to power on/off a Raspberry Pi (powered through GPIO), I'm using it on the low side. (Both share the same +5V rail).

When I measure the current the raspberry pi's current draw, it seems limited, and it doesn't operate properly.

On that MOSFET:

  • Gate: To AVR digital pin (and pulled low with a 10k resistor)
  • Drain: To Raspberry Pi GPIO ground
  • Source: To GND

Naturally, my 5v from my power supply is directly to the raspberry pi GPIO 5v.

As a kind of experiment control: I just power the raspberry pi directly from my power supply 5v/Ground. I measure the raspberry pi draws through 5v with a multimeter, and during power up it fluctuates from 0.15 A (up to about 0.45 A) and settles at about 0.35 A

However, when I measure how much current the raspberry pi draws when connected to the MOSFET and when I turn the gate on -- it seems the current is limited and it gets up to about 0.30 A (approx) and never gets higher, and the raspberry pi seems to never fully power on.

I'm curious if I'm missing something here with trying to power this on. It is indeed a logic-level MOSFET, but, as an experiment I've tried powering the MOSFET at varying voltages with a bench power supply -- but no noticeable change by using more voltage (up to 10V I tried.)

Granted, I am more of a programmer and electronics technician -- so I appreciate any electronics engineering input and advice, but, pragmatic solutions are most appreciated. I'm just so puzzled as the MOSFET should be rated up to 60A and I would've thought that just applying a logic-level voltage I would've been able to draw more current through the mosfet.

Here's a diagram of the circuit (please note: I can re-create this situation without the micro at all, and just with the raspberry pi + bench power + mosfet, as diagramed). Note that in this representation the raspi gpio connection is simplified and in this diagram pin 1 on the jumper = 5v, and pin 2 = GND.

enter image description here

2 added 6 characters in body
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