Datasheet

 2005-2012 Microchip Technology Inc. DS21985D-page 35
MCP131X/2X
5.0 APPLICATION INFORMATION
This section shows application-related information that
may be useful for your particular design requirements.
5.1 Supply Monitor Noise Sensitivity
The MCP131X/2X devices are optimized for fast
response to negative-going changes in V
DD
. Systems
with an inordinate amount of electrical noise on V
DD
(such as systems using relays) may require a 0.01 µF
or 0.1 µF bypass capacitor to reduce detection
sensitivity. This capacitor should be installed as close
to the MCP131X/2X as possible to keep the capacitor
lead length short.
FIGURE 5-1: Typical Application Circuit
with Bypass Capacitor.
5.2 Conventional Voltage Monitoring
Figure 5-2 and Figure 5-3 show the MCP131X/2X in
conventional voltage monitoring applications.
FIGURE 5-2: Battery Voltage Monitor.
FIGURE 5-3: Power Good Monitor.
5.3 Using in PIC
®
Microcontroller,
ICSP™ Applications
Figure 5-4 shows the typical application circuit for using
the MCP132X for a voltage supervisory function when
the PIC
®
microcontroller will be programmed via the In-
Circuit Serial Programming™ (ICSP™) feature. Addi-
tional information is available in TB087, “Using Voltage
Supervisors with PIC
®
Microcontroller Systems which
Implement In-Circuit Serial Programming™”
(DS91087).
FIGURE 5-4: Typical Application Circuit
for PIC
®
Microcontroller with the ICSP™ Feature.
MCP131X/2X
V
DD
RST
V
SS
0.1 µF
RST
WDI
MR
V
DD
RST
V
SS
BATLOW
MCP131X/2X
+
––
V
DD
RST
V
SS
Power Good
MCP131X/2X
+
–
Pwr
Sply
Note: This operation can only be done using the
device with the Open-Drain RST
pin
(MCP1320, MCP1321, and MCP1322).
Devices that have the internal pull-up
resistor are not recommended due to the
current path of the internal pull-up resistor.
Note: It is recommended that the current into the
RST
pin be current limited by a 1 k
resistor.
MCP132X
V
DD
V
DD
/V
PP
V
DD
RST
MCLR
Reset input)
(Active-Low)
V
SS
V
SS
PIC
®
Microcontroller
R
PU
0.1 µF
1k