MCP1316 Microchip Technology, MCP1316 Datasheet - Page 23

• Manufacturer Part Number: MCP1316
• Description: Voltage Supervisor
• Manufacturer: Microchip Technology

4.0
For many of today’s microcontroller applications, care
must be taken to prevent low-power conditions that can
cause many different system problems. The most
common causes are brown-out conditions, where the
system supply drops below the operating level momen-
tarily. The second most common cause is when a
slowly
microcontroller to begin executing instructions without
sufficient voltage to sustain volatile memory (RAM),
thus producing indeterminate results. Figure 4-1 shows
a typical application circuit.
The MCP131X/2X family is voltage supervisor devices
designed to keep a microcontroller in Reset until the
system voltage has reached and stabilized at the
proper level for reliable system operation. These
devices also operate as protection from brown-out
conditions when the system supply voltage drops
below a safe operating level.
Some MCP131X/2X family members include a Watch-
dog Timer feature that after being enabled (by a falling
edge on the WDI pin), monitors the WDI pin for falling
edges. If an edge transition is not detected within the
expected timeframe, the MCP131X/2X devices will
force the Reset pin active. This is useful to ensure that
the embedded system’s Host Controller program is
operating as expected.
Some MCP131X/2X family members include a Manual
Reset feature that allows a push button switch to be
directly connected to the MCP131X/2X devices (on the
MR pin). This allows the system to easily be reset from
the external control of the push button switch.
A superset block diagram is shown in Figure 4-2, with
device specific block diagrams shown in Figure 4-3
through Figure 4-12.
© 2005 Microchip Technology Inc.
OPERATIONAL DESCRIPTION
decaying
power
supply
causes
the
FIGURE 4-1:
FIGURE 4-2:
MR
WDI
0.1
μF
Push button
switch
V
Note: Features available depend on the device.
Note 1: Resistor R
DD
2: Not all devices offer the active-high
MCP13XX
MR
MCP1320, MCP1321 or MCP1322 due
to the open-drain output.
Resistor R
the MCP1316M, MCP1318M or
MCP1319M due to the internal pull-up
resistor.
The MCP1316, MCP1317, MCP1318
and MCP1319 do not require the
external pull-up resistor.
Reset output pin.
+
–
V
V
Noise Filter
Watchdog
RST
Comparator
SS
DD
RST
Reference
Voltage
WDI
MCP131X/2X
(2)
Typical Application Circuit.
Family Block Diagram
V
PU
PU
To system
device that
requires active-
high resets
DD
may be required with the
may not be required with
R
PU
(1)
Output
Driver
Microcontroller
MCLR
(Reset input)
(active-low)
DS21985A-page 23
I/O
PICmicro
V
V
SS
DD
RST
RST
V
®
SS