Dual High Side Micropower MOSFET Driver

The LTC1155 dual high side gate driver allows using low cost N-channel FETs for high side switching applications. An internal charge pump boosts the gate above the positive rail, fully enhancing an N-channel MOSFET with no external components. Micropower operation, with 8μA standby current and 85μA operating current, allows use in virtually all systems with maximum efficiency.

Included on-chip is overcurrent sensing to provide automatic shutdown in case of short circuits. A time delay can be added in series with the current sense to prevent false triggering on high in-rush loads such as capacitors and incandescent lamps.

The LTC1155 operates off of a 4.5V to 18V supply input and safely drives the gates of virtually all FETs. The LTC1155 is well suited for low voltage (battery-powered) applications, particularly where micropower “sleep” operation is required.

The LTC1155 is available in both 8-pin PDIP and 8-pin SO packages.

APPLICATIONS

* Laptop Power Bus Switching

* SCSI Termination Power Switching

* Cellular Phone Power Management

* P-Channel Switch Replacement

* Relay and Solenoid Drivers

* Low Frequency Half H-Bridge

* Motor Speed and Torque Control

* Fully Enhances N-Channel Power MOSFETs

* 8μA Standby Current

* 85μA ON Current

* Short-Circuit Protection

* Wide Power Supply Range: 4.5V to 18V