high power consumption in sleep mode for PIC

[lnzsy]

Sleep power consumption

Hi guys,

I tried to measure the current when my PIC16F727 is in sleep mode but it turns out that the current is like 4.3 uA, which is much higher than 50nA, the one specified in the datasheet.

Should I just use SLEEP() function or I need to add some other things? Is there only one sleep mode or there are several of them?

Thanks in advance!
Nereus

 

[doraemon]

Re: Sleep power consumption

Hello!

I don't know about PIC, I am a MSP430 user. However, there are a few issues
that may be the same.

Check the documentation. If the I/O port is enabled, it may increase the
power consumption. (i.e. for instance, the consumption is different if the
port is in input mode vs output mode).

Also check the other components on your hardware. Are you sure that none of
them has an influence on the power consumption?

Dora.

 

[FvM]

Sleep power consumption

The nA specification is for LF type only. Do you have it?

Any current consuming function, e.g. BOR, must be disabled, all pins must be at fixed level to achieve the low consumption.
Read the datasheet for details.

In any case, individual devices can have higher current than specified typical values. You have to consider this when
planning a product.

 

[lnzsy]

Re: Sleep power consumption

Hi FvM, thanks for your responce.

But I think although the power in the datasheet is for 16LF, it shouldn't be too different from 16F. If you see #16 in https://ww1.microchip.com/downloads/en/DeviceDoc/01146B_chapter 2.pdf
you will see that they say most of Microchip devices consume less than 50nA. Also, do you know how to make the chip in deep sleep mode?

Thanks a lot for the help. I really appreciate it.
Nereus

The nA specification is for LF type only. Do you have it?

Any current consuming function, e.g. BOR, must be disabled, all pins must be at fixed level to achieve the low consumption.
Read the datasheet for details.

In any case, individual devices can have higher current than specified typical values. You have to consider this when
planning a product.

 

[M!k]

Re: Sleep power consumption

I know that a 16F887 is by any means below 1uA.
Your current of a few uA could be a floating input pin. Please note FvM's advise:

... all pins must be at fixed level to achieve the low consumption.

So tie open input pins to gnd or vcc or just configure them as outputs.
Btw. you'll find them by touching them. The current will change then.