MOSFET without gate resistors?

I am trying to develop a schematic with minimal components. The board would drive a N-MOSFET from a microcontroller, and I am wondering if I can omit the gate resistors (pulldown for "default" off, series from microcontroller to gate).

The transistor is essentially charging a capacitor whose charge will be used to provide high current for a very short time (20mA at 3V for 15ms to downstream).

The rationale behind omitting the gate resistors is the following:

• 4.7kOhm current limiting resistor (VCC from a 3V coin cell, limit high current which reduces coin cell life). This would mean low drain current.
• Transistor very close to microcontroller, expected low parasitic noise.

My question is: would this design work?

• Are you sure a N FET works as Q1? The more voltage there is on capacitor, the less there is Vgs to keep transistor on, right? Even an ideal P FET that turns fully on would take roughly 2.35 seconds to charge the 100uF capacitor to 99% via 4k7 resistor. Also do you think 100uF is large enough to give 20mA for 30ms? It would ideally need 6V change on capacitor. Dec 22, 2020 at 8:34
• I computed the current using I = C*dV/dt, where C=100uF, dV=3V , dt=20ms. You're right, it needs about 2s to charge after 5tau, which is fine. I'm not sure I understand the rest of the reasoning. Dec 22, 2020 at 8:39
• EDIT: You're right, redid my calculations, it would drive 20mA for 15ms. Dec 22, 2020 at 8:41
• @MihaiGalos When the N-FET turns on, it's source will begin rising toward VCC. With the gate voltage fixed, coming from the micro, this means the gate-source voltage will decrease, preventing the FET from fully turning on. Dec 22, 2020 at 8:45
• you can use your MCU as a pull down, so as long as the brief power-on uncertainty period doesn't blow anything up if the FET is one state or the other, it's fine. Dec 23, 2020 at 0:09