CFAG12864-B POWER ISSUE

[RacerX10]

I'm using the topic 128x64 display in a battery powered application so I need to be able to go in to a SLEEP mode in my device.

I'm finding that when I get everything powered down, pins 14 and 12 of the display (CS1 and RST) are drawing a significant amount of current (3.5 mA)

Those are the only pins I'm experiencing this problem on.

Thanks for ideas you may have on this issue.

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[CF Tech]

Can you set those to high-impedance (inputs) on your processor? That should stop any current flowing.

 

[RacerX10]

Can you set those to high-impedance (inputs) on your processor? That should stop any current flowing.

Trying that, will report back results.

Thanks !

 

[RacerX10]

Thanks for the advice. That definitely got me going in the right direction, as I'm down to 400uA draw.

However, I've found that by disconnecting either of those three pins (RS or CS1 or RST) I can get down to 60uA draw in sleep mode, which is closer to what I'm expecting.

Any more ideas ?

Thanks again !

 

[RacerX10]

I think I've figured it out.

I was powering the display from PIC pin so that I can shut it down to save power. I was driving the supply line on the display LOW to shut it down, I think that was fighting with the levels asserted on those 3 pins for whatever reason and causing a ground-loop sorta thing.

I've changed it so that instead of driving the +5v supply LOW from the PIC pin, I switch it to an input and that has dropped my current consumption down to 60 or 80 uA from the 400uA I was seeing before.