PIC18F64J90 low power design problem

LourenceGuo · Joined: 14 Feb 2008 Posts: 7 Location: China, Shenzhen

Dear All.
We try to use PIC18F64J90 to design a battery powered low power equipment.
We used most of the I/O as LCD drive segments. The LCD is a 88 pixels segment LCD. W/ AN0,AN1,AN2 as ADC function, use to detect the battery power and other analog parameters, the reference voltage is 1.22V and controllable(when we do not use the ADC function, we can turn off the power for reference voltage). Use another I/O as infrared receive function. We connected a 32.768KHz crystal on T1OSI and T1OSO for T1 RTC function.
The crystal we used is 1MHz INRC.
We try to make the MCU into sleep mode in most of the time to save power. We use the CCS compiler.

The code we use to get into sleep mode is:

#bit IDLEN=0xFD3.7
IDLEN=0;
sleep();

After we tried these orders, the MCU stopped, but the consumption current only changed from 3.6mA to 3.0mA.
We hope the current consumption can reduce to 100uA or more smaller.

Any reply for this topic will be gratefully appreciated!
Thanks!
_________________
All things are difficult before they are easy.

LourenceGuo · Joined: 14 Feb 2008 Posts: 7 Location: China, Shenzhen

Look forward for the reply. Thanks!
_________________
All things are difficult before they are easy.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

LourenceGuo · Joined: 14 Feb 2008 Posts: 7 Location: China, Shenzhen

According to the attached forum, we do some setting for the corresponding pins, the current decreased to about 74uA.
But the current did not have more reduce when we use: sleep();
We try to use #fuses nobrownout; but there is not such fuse in 18f64j90 head file.
Anyway, thank you for your reply, it is great help. We will do more reseach to reduce more current in sleep mode.
_________________
All things are difficult before they are easy.