The TPS20xxB power-distribution switches are intended for
applications where heavy capacitive loads and short circuits are likely to be encountered. These
devices incorporates 70-mΩ N-channel MOSFET power switches for power-distribution systems that
require multiple power switches in a single package. Each switch is controlled by a logic enable
input. Gate drive is provided by an internal charge pump designed to control the power-switch rise
times and fall times to minimize current surges during switching. The charge pump requires no
external components and allows operation from supplies as low as 2.7 V.
When the output load exceeds the current-limit threshold or a short is present, the
device limits the output current to a safe level by switching into a constant-current mode, pulling
the overcurrent (OCx) logic output low. When continuous heavy overloads and
short circuits increase the power dissipation in the switch, causing the junction temperature to
rise, a thermal protection circuit shuts off the switch to prevent damage. Recovery from a thermal
shutdown is automatic once the device has cooled sufficiently. Internal circuitry ensures that the
switch remains off until valid input voltage is present. This power-distribution switch is designed
to set current limit at 1 A (typical).