2004-2013 Microchip Technology Inc. DS21896C-page 13
MCP1630/MCP1630V
4.6 Undervoltage Lockout (UVLO)
When the input voltage (V
IN
) is less than the UVLO
threshold, the V
EXT
is held in the low state. This will
ensure that, if the voltage is not adequate to operate
the MCP1630/V, the main power supply switch will be
held in the off state. When the UVLO threshold is
exceeded, there is some hysteresis in the input voltage
prior to the UVLO off threshold being reached. The
typical hysteresis is 75 mV. Typically, the MCP1630 will
not start operating until the input voltage at V
IN
is
between 3.0V and 3.1V.
4.7 Overtemperature Protection
To protect the V
EXT
output if shorted to V
IN
or GND, the
MCP1630/V V
EXT
output will be high-impedance if the
junction temperature is above the thermal shutdown
threshold. There is an internal 100 k pull-down resis-
tor connected from V
EXT
to ground to provide some
pull-down during overtemperature conditions. The
protection is set to 150°C (typ.), with a hysteresis of
18°C.
