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I am using the AO3415 to do high-side switching.

My aim is to reduce power consumption as this low-power device should run for ages on a single battery. System quiescent current is less than 5 μA. (VCC is 5 V)

What is the smallest pull-down resistor value I can use to reduce power consumption but not cause problems?

This P-channel MOSFET is switched a maximum of once every second.

I have checked How do I calculate the required value for a pull-up resistor? and Calculating the pulldown resistance for a given MOSFET's gate among others but am not given a concrete value or formula.

[![enter image description here][1]][1]

A 100 kΩ resistor causes 50 μA of loss when the gate is driven high, which is far too much, especially compared to the rest of the system. The gate is high half the time.

How low can I go? 100 kΩ? 470 kΩ? 1 MΩ? 4.7 MΩ? Even lower?

Velvel
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UnknownDagger
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    You say P-channel, but link to an N-channel MOSFET datasheet. Then you say "switching highside" (which *would* use a P-channel device), but show us an N-channel transistor switching on the low side. What's really going on? – Simon Fitch May 31 '23 at 04:48
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    (You use lowest/lower for a desirable resistor value, but that's for *current*. You list values in *increasing* order. (*If* the gate was sure to be driven to either source level or saturation, you don't *need* a pull-to source resistor at all. I'd try 22 M if I found one - you need to keep "the gate-note" clean and dry, anyway.)) – greybeard May 31 '23 at 08:11
  • @SimonFitch I've corrected the name now, it's a P-channel MOSFET – UnknownDagger May 31 '23 at 10:49
  • @greybeard the gate isn't driven by push-pull, it's either connected to 5V or left floating, hence the pull-down is needed – UnknownDagger May 31 '23 at 10:52
  • Schematic needed. How fast do you need to switch? How much switching losses are you willing to accept? – winny May 31 '23 at 11:02
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    You've removed the image URL from the bottom of the mark-down. If you put it back, please update it to show the intended use of the new P-channel MOSFET, and include both control signal voltages, and the load's supply voltage, because this will be important for high-side switching with PMOS. – Simon Fitch May 31 '23 at 11:02

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