Microchip Technology MCU PIC PIC18F87K22-I/PTRSL TQFP-80 MCP PIC18F87K22-I/PTRSL Data Sheet

DS39960D-page 422

 2009-2011 Microchip Technology Inc.

28.3.2

OPERATION OF REGULATOR IN 
SLEEP

The difference in the two regulators’ operation arises
with Sleep mode. The ultra low-power regulator gives
the device the lowest current in the Regulator Enabled
mode.
The on-chip regulator can go into a lower power mode,
when the device goes to Sleep, by setting the REGSLP
bit (WDTCON<7>). This puts the regulator in a Standby
mode so that the device consumes much less current.
The on-chip regulator can also go into the Ultra Low-
Power mode, which consumes the lowest current
possible with the regulator enabled. This mode is
controlled by the RETEN bit (CONFIG1L<0>) and
SRETEN bit (WDTCON<4>).

The various modes of regulator operation are shown in

When the ultra low-power regulator is in Sleep mode,
the internal reference voltages in the chip will be shut
off and any interrupts referring to the internal reference
will not wake up the device. If the BOR or LVD is
enabled, the regulator will keep the internal references
on and the lowest possible current will not be achieved.
When using the ultra low-power regulator in Sleep
mode, the device will take about 250

s, typical, to start

executing the code after it wakes up.

Enabled 

Normal Operation (Sleep)

0

x

1

Enabled

Low-Power mode (Sleep)

1

x

1

Enabled

Normal Operation (Sleep)

0

0

x

Enabled

Low-Power mode (Sleep)

1

0

x

Enabled

Ultra Low-Power mode (Sleep)

x

1

0

x = Indicates that V

IT

 status is invalid.