1 Features
1• Drives Both a High-Side and Low-Side N-Channel
MOSFET
• 1-A Peak Output Current (1.0-A Sink and 1.0-A
Source)
• Inputs Compatible With Independent TTL and
CMOS
• Bootstrap Supply Voltage to 108-V DC
• Fast Propagation Times (30 ns Typical)
• Drives 1000-pF Load With 15-ns Rise and Fall
Times
• Excellent Propagation Delay Matching (2 ns
Typical)
• Supply Rail Undervoltage Lockout
• Low Power Consumption
• 8-Pin SOIC and Thermally-Enhanced 8-Pin
WSON Package

2 Applications
• Current-Fed, Push-Pull Converters
• Half- and Full-Bridge Power Converters
• Solid-State Motor Drives
• Two-Switch Forward Power Converters

3 Description
The LM5109B device is a cost-effective, high-voltage
gate driver designed to drive both the high-side and
the low-side N-channel MOSFETs in a synchronous
buck or a half-bridge configuration. The floating
high-side driver is capable of working with rail
voltages up to 90 V. The outputs are independently
controlled with cost-effective TTL and
CMOS-compatible input thresholds. The robust level shift technology operates at high speed while
consuming low power and providing clean level
transitions from the control input logic to the high-side
gate driver. Undervoltage lockout is provided on both
the low-side and the high-side power rails. The
device is available in the 8-pin SOIC and thermally- enhanced 8-pin WSON packages.