1 Features

• 650V GaN power-FET half bridge

• 230mΩ low-side and high-side GaN FETs

• Integrated gate drivers with <100ns low

propagation delays

• Programmable turn-on slew rate control

• Current-sense emulation with high-bandwidth and

high accuracy

• Low-side referenced (INH) and high-side

referenced (GDH) high-side gate drive pins

• Low-side (INL) / high-side (INH) gate-drive

interlock

• High-side (INH) gate-drive signal level shifter

• Smart-switched bootstrap diode function

• High-side start up: <8μs

• Low-side / high-side cycle-by-cycle overcurrent

protection

• Overtemperature protection

• AUX idle quiescent current: 250μA

• AUX standby quiescent current: 50μA

• BST idle quiescent current: 70μA

• 8mm × 6mm QFN package with dual thermal pads

2 Applications

• AC/DC adapters and chargers

• AC/DC auxiliary power supplies

• Mobile wall charger design

• USB wall power outlet

3 Description

The LMG2656 is a 650V 230mΩ GaN power-FET

half bridge. The LMG2656 simplifies design, reduces

component count, and reduces board space by

integrating half-bridge power FETs, gate drivers,

bootstrap FET, and high-side gate-drive level shifter

in a 6mm by 8mm QFN package.

Programmable turn-on slew rates provide EMI and

ringing control. The low-side current-sense emulation

reduces power dissipation compared to the traditional

current-sense resistor and allows the low-side thermal

pad to be connected to PCB power ground.

The high-side GaN power FET can be controlled with

either the low-side referenced gate-drive pin (INH)

or the high-side referenced gate-drive pin (GDH).

The high-side gate-drive signal level shifter reliably

transmits the INH pin signal to the high-side gate

driver in challenging power switching environments.

The smart-switched GaN bootstrap FET has no diode

forward-voltage drop, avoids overcharging the highside

supply, and has zero reverse-recovery charge.

The LMG2656 supports converter light-load efficiency

requirements and burst-mode operation with low

quiescent currents and fast start-up times. Protection

features include FET turn-on interlock, under-voltage

lockout (UVLO), cycle-by-cycle current limit, and overtemperature

shut down. Ultra low slew rate setting

supports motor drive applications.