L
Hello!
I'm working on a project that basically includes an avr microcontroller
and a few ics around it : including a digital variable resistor e.t.c.
Some of my peripherial ICs have a shutdown option which puts them into a low-power mode, some don't. The ICs that do, sometimes still consume too much current for my taste.
Just to give you an idea : the avr mcu i am using consumes 400 nAmps in deep sleep mode, so when I have a digital pot that consumes 0.5 mA in low power mode, you can see how that can become the bottleneck.
I've been trying to use power-mosfets to control the power supply to those ics, but not sure if i am reinventing the wheel here: some of the ICs have multiple ground/vcc connections, each one is connected using a capacitor to the ground.
My question is: what would be the best practice in controlling the power supply from an mcu to a peripherial IC using a transistor: do i hook a p-channel at the vcc end, or a n-channel at the ground end, or perhaps is it something else completely.
Would appreciate your feedback.
I'm working on a project that basically includes an avr microcontroller
and a few ics around it : including a digital variable resistor e.t.c.
Some of my peripherial ICs have a shutdown option which puts them into a low-power mode, some don't. The ICs that do, sometimes still consume too much current for my taste.
Just to give you an idea : the avr mcu i am using consumes 400 nAmps in deep sleep mode, so when I have a digital pot that consumes 0.5 mA in low power mode, you can see how that can become the bottleneck.
I've been trying to use power-mosfets to control the power supply to those ics, but not sure if i am reinventing the wheel here: some of the ICs have multiple ground/vcc connections, each one is connected using a capacitor to the ground.
My question is: what would be the best practice in controlling the power supply from an mcu to a peripherial IC using a transistor: do i hook a p-channel at the vcc end, or a n-channel at the ground end, or perhaps is it something else completely.
Would appreciate your feedback.