PIC10F222 Microchip Technology Inc., PIC10F222 Datasheet - Page 38

• Manufacturer Part Number: PIC10F222
• Description: High-performance Microcontrollers With 8-bit A/d
• Manufacturer: Microchip Technology Inc.

PIC10F220/222
8.8
A Brown-out is a condition where device power (V
dips below its minimum value, but not to zero, and then
recovers. The device should be reset in the event of a
Brown-out.
To reset PIC10F220/222 devices when a Brown-out
occurs, external Brown-out protection circuits may be
built, as shown in Figure 8-7 and Figure 8-8.
FIGURE 8-7:
FIGURE 8-8:
DS41270E-page 40
Note 1:
Note 1:
33k
2:
2:
V
Reset on Brown-out
DD
R1
R2
This circuit will activate Reset when V
below Vz + 0.7V (where Vz = Zener voltage).
Pin must be configured as MCLR.
This brown-out circuit is less expensive,
although less accurate. Transistor Q1 turns
off when V
that:
Pin must be configured as MCLR.
V
DD
V
10k
DD
•
DD
BROWN-OUT
PROTECTION CIRCUIT 1
BROWN-OUT
PROTECTION CIRCUIT 2
R1 + R2
Q1
is below a certain level such
40k
R1
MCLR
(1)
V
Q1
40k
DD
V
DD
MCLR
(1)
(2)
= 0.7V
PIC10F22X
(2)
PIC10F22X
DD
goes
DD
)
FIGURE 8-9:
8.9
A device may be powered down (Sleep) and later
powered up (wake-up from Sleep).
8.9.1
The Power-Down mode is entered by executing a
SLEEP instruction.
If enabled, the Watchdog Timer will be cleared but
keeps running, the TO bit (STATUS<4>) is set, the PD
bit (STATUS<3>) is cleared and the oscillator driver is
turned off. The I/O ports maintain the status they had
before the SLEEP instruction was executed (driving
high, driving low or high-impedance).
For lowest current consumption while powered down,
the T0CKI input should be at V
MCLR/V
enabled.
Note:
Note 1: This Brown-out Protection circuit employs
V
SS
PP
Power-down Mode (Sleep)
MCP809
RST
2: Pin must be configured as MCLR.
pin must be at a logic high level if MCLR is
SLEEP
A Reset generated by a WDT time-out
does not drive the MCLR pin low.
Microchip Technology’s MCP809 micro-
controller supervisor. There are 7 different
trip point selections to accommodate 5V to
3V systems.
V
V
DD
DD
Capacitor
Bypass
BROWN-OUT
PROTECTION CIRCUIT 3
© 2007 Microchip Technology Inc.
DD
or V
V
PIC10F22X
DD
SS
MCLR
and the GP3/
(2)