LM5104

High Voltage Half-Bridge Gate Driver with Adaptive

Delay

General Description

The LM5104 High Voltage Gate Driver is designed to drive

both the high side and the low side N-Channel MOSFETs in

a synchronous buck configuration. The floating high-side

driver is capable of working with supply voltages up to 100V.

The high side and low side gate drivers are controlled from a

single input. Each change in state is controlled in an adap-

tive manner to prevent shoot-through issues. In addition to

the adaptive transition timing, an additional delay time can

be added, proportional to an external setting resistor. An

integrated high voltage diode is provided to charge high side

gate drive bootstrap capacitor. A robust level shifter operates

at high speed while consuming low power and providing

clean level transitions from the control logic to the high side

gate driver. Under-voltage lockout is provided on both the

low side and the high side power rails. This device is avail-

able in the standard SOIC-8 pin and the LLP-10 pin pack-

ages.

Features

n

Drives both a high side and low side N-channel

MOSFET

n

Adaptive rising and falling edges with programmable

additional delay

n

Single input control

n

Bootstrap supply voltage range up to 118V DC

n

Fast turn-off propagation delay (25 ns typical)

n

Drives 1000 pF loads with 15 ns rise and fall times

n

Supply rail under-voltage lockout

Typical Applications

n

Current Fed Push-Pull Power Converters

n

High Voltage Buck Regulators

n

Active Clamp Forward Power Converters

n

Half and Full Bridge Converters

Package

n

SOIC-8

n

LLP-10 (4 mmx4mm)

Simplified Block Diagram

20089003

FIGURE 1.

January 2004

© 2004 National Semiconductor Corporation

DS200890

www.national.com