MCP1316 Microchip Technology, MCP1316 Datasheet - Page 22

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

MCP131X/2X
3.1
V
input voltage. Typically, the circuit ground is used.
3.2
V
voltage level that requires monitoring.
3.3
There are four types of Reset output pins. These are:
1.
2.
3.
4.
Some devices have both an active-low and active-high
Reset output.
3.3.1
The RST open-drain output remains low while V
below the Reset voltage threshold (V
device voltage (V
V
delay timer (T
will float, and an external pull-up resistor is required to
bring the output to the high state.
3.3.2
The RST open-drain output remains low while V
below the Reset voltage threshold (V
device voltage (V
V
delay timer (T
will be pulled high by an internal pull-up resistor (typi-
cally 4.7 k ).
3.3.3
The RST push-pull output remains low while V
below the Reset voltage threshold (V
device voltage (V
V
delay timer (T
will be driven to the high state.
3.3.4
The RST push-pull output remains high while V
below the Reset voltage threshold (V
device voltage (V
V
delay timer (T
will be driven to the low state.
DS21985A-page 22
SS
DD
HYS
HYS
HYS
HYS
Open-Drain active-low Reset, External pull-up
resistor required
Open-Drain active-low Reset, Internal pull-up
resistor
Push-Pull active-low Reset
Push-Pull active-high Reset
provides the negative reference for the analog
can be used for power supply monitoring or a
), the device will remain in Reset for the Reset
), the device will remain in Reset for the Reset
), the device will remain in Reset for the Reset
), the device will remain in Reset for the Reset
Ground Terminal (V
Supply Voltage (V
Reset Output (RST and RST)
ACTIVE-LOW (RST) - OPEN-DRAIN,
EXTERNAL PULL-UP RESISTOR
ACTIVE-LOW (RST) - OPEN-DRAIN,
INTERNAL PULL-UP RESISTOR
ACTIVE-LOW (RST) - PUSH-PULL
ACTIVE-HIGH (RST) - PUSH-PULL
RST
RST
RST
RST
). After that time expires, the RST pin
). After that time expires, the RST pin
). After that time expires, the RST pin
). After that time expires, the RST pin
DD
DD
DD
DD
) returns to a high level (V
) returns to a high level (V
) returns to a high level (V
) returns to a high level (V
DD
SS
)
)
TRIP
TRIP
TRIP
TRIP
). Once the
). Once the
). Once the
). Once the
TRIP
TRIP
TRIP
TRIP
DD
DD
DD
DD
is
is
is
is
+
+
+
+
3.4
The Manual Reset (MR) input pin allows a push button
switch to easily be connected to the system. When the
push button is depressed, it forces a system Reset.
This pin has circuitry that filters noise that may be
present on the MR signal.
The MR pin is active-low and has an internal pull-up
resistor.
3.5
In some systems, it is desirable to have an external
Watchdog Timer to monitor the operation of the sys-
tem. This is done by requiring the embedded controller
to “pet” the Watchdog Timer within a predetermined
time frame (T
within this time frame, the MCP131X/2X will force the
Reset pin(s) active.
The embedded controller “pets” the MCP131X/2X by
forcing an edge transition on the WDI pin. The WDT
Timer is activated by the first falling edge on the WDI
pin.
The standard offering devices have a typical Watchdog
Timer period (T
able Watchdog Timer periods.
Manual Reset Input (MR)
Watchdog Input
WD
WD
). If the MCP131X/2X is not “petted”
) of 1.6 s. Table 1-3 shows the avail-
© 2005 Microchip Technology Inc.