Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Problem with Ultra Low Power Wake Up (ULPWU) - PIC16F883

Status
Not open for further replies.

hbrault

New Member
Hi all,
I am starting my first battery powered project and of course I would like to keep the battery running as long as possible. To do that I obviously need to minimize the power consumption. The application is a basic temperature reading. Every 5 minutes or so is good enough.

I ran a bunch of tests and this is what I found:
Once I enter sleep mode,
- I did verify that the current sunk by RA0 is indeed < 200nA
- But the total current used by the PIC is around 2µA @ 2.5v

So here is my question: how do I reduce these 2µA?
Before going through the obvious, let me add this:
- I am using a small test board. Only RA0 is connected.
- All ports are configured as digital output
- I checked that on reset (and in conformity with the datasheet)
- RB weak pull ups are disabled
- the comparator modules are disabled
- the ADC is disabled
- Timer1 and 2 are disabled
- The CCP module i disabled
- The serial port is disabled
- The SSP module is disabled

So what did I forget? How do I get to a sub 1 μA system as the AN879 from microchip states: "A typical smoke detector or Tire Pressure Monitoring (TPM) system with sub 1 μA current consumption can be achieved"

Thank you all. Any suggestion will be welcome.
 
Do you know that at 2 uA your PIC can run in sleep mode for > 5 years on an CR2032 button cell?
 
Last edited:
Not sure on the 16 series parts, but on the 18 and 24 series parts, you need to make sure things like BOR and WDT are disabled to get minimal consumption. Even so, the two or three micro-amps I usually have no trouble getting them down to has been plenty low enough for my battery powered applications. The XL versions available both in the 18 and 24 series are supposed to go into the nA. If you really need to get your power consumption down that low, you should look into using one of the 18 series XL parts. In general, 18 series parts are actually nicer to work with than the 16 series. My favorite is the 24 and companion DSP series. Those are brilliant parts IMO.
 
Thank you all for your replies. I can happily live with the 2µA, Based on microchip doc I was just hoping I could do better.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top