Datasheet

© 2007 Microchip Technology Inc. DS41232D-page 87
PIC12F635/PIC16F636/639
8.0 PROGRAMMABLE
LOW-VOLTAGE DETECT
(PLVD) MODULE
The Programmable Low-Voltage Detect (PLVD)
module is a power supply detector which monitors the
internal power supply. This module is typically used in
key fobs and other devices, where certain actions
need to be taken as a result of a falling battery voltage.
The PLVD module includes the following capabilities:
• Eight programmable trip points
• Interrupt on falling V
DD
• Stable reference indication
• Operation during Sleep
A Block diagram of the PLVD module is shown in
Figure 8-1.
FIGURE 8-1: PLVD BLOCK DIAGRAM
FIGURE 8-2: PLVD OPERATION
LVDL<2:0>
8-to-1
8 Stages
LVDEN
VDD
7
6
2
1
0
Analog MUX
+
-
LVDIF
Voltage
Generator
det
Reference
PLVD Trip Point
LVDIF
VDD
Set by
Hardware
Cleared by
Software