features
135-mW -Maximum (5-V Input) High-Side
MOSFET Switch
250 mA Continuous Current
Short-Circuit and Thermal Protection With
Overcurrent Logic Output
Operating Range . . . 2.7-V to 5.5-V
Logic-Level Enable Input
2.5-ms Typical Rise Time
Undervoltage Lockout
10 mA Maximum Standby Supply Current
Bidirectional Switch
Available in 8-pin SOIC and PDIP Packages
Ambient Temperature Range, –40°C to 85°C
2-kV Human-Body-Model, 200-V
Machine-Model ESD Protection

typical applications
Notebook, Desktop and Palmtop PCs
Monitors, Keyboards, Scanners, and
Printers
Digital Cameras, Phones, and PBXs
Hot-Insertion Applications

description
The TPS2045 and TPS2055 power-distribution switches are intended for applications where heavy capacitive
loads and short circuits are likely. Each of these 135-mW N-channel MOSFET high-side power switches is
controlled by a logic enable compatible with 5-V and 3-V logic. Gate drive is provided by an internal charge pump
that controls 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 TPS2045 and TPS2055 limit
the output current to a safe level by switching into a constant-current mode, pulling the overcurrent (OC) 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 in overcurrent to prevent
damage. Recovery from a thermal shutdown is automatic once the device has cooled sufficiently. Internal
circuitry ensures the switch remains off until valid input voltage is present.
The TPS2045 and TPS2055 are designed to limit at 0.44-A load. These power-distribution switches, available
in 8-pin small-outline integrated circuit (SOIC) and 8-pin plastic dual-in-line packages (PDIP), operate over an
ambient temperature range of –40°C to 85°C.