/diy/ - Do It Yourself

Okay big brain time.
So after thinking for a while on how to power my micro that sleeps most of the time but needs bursts of 200ma i came up with this.
I bought ldo that can supply 500ma and only has 170ua quiescent current. That is very low but since the sleeping circuit only consumes 3ua that is a MASSIVE waste, the ldo is wasting 56x more power than rest of circuit.
I looked at some voltage references and stuff as a power option solution but then i came up with this:
Press button, P fet turns on, ldo charges caps and supplies micro with power, micro then sets the P fet gate to low and i can let go off the button and the circuit stays on.
The micro does any high current operations it needs to do, then sets P fet gate to HIGH, which shuts down the LDO, making its current draw 0.
The micro goes to sleep for 4 seconds (circuit only uses 10ua in deep sleep) power is supplied by the caps. After 4 sec micro wakes up, pulls P fet gate LOW, ldo turns on, recharges caps, micro does more work, goes to sleep and so on.
This way i get all the benefits of using an LDO while wasting at most few nano amps to ceramic caps leakage currents.

What do you think? Seems to work on paper. I ran the math and the numbers check out.