650V 105mΩ GaN half-bridge with integrated driver, protection and current sense

The LMG2640 is

a 650V GaN power-FET half bridge intended for switch mode power supply applications. The

LMG2640 simplifies design, reduces component count, and

reduces board space by integrating half-bridge power FETs, gate drivers, bootstrap diode,

and high-side gate-drive level shifter in a 9mm by 7mm QFN package.

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

the cooling PCB power ground.

The high-side gate-drive signal level

shifter eliminates noise and burst-mode power dissipation problems found with external

solutions. The smart-switched GaN bootstrap FET has no diode forward-voltage drop, avoids

overcharging the high-side supply, and has zero reverse-recovery charge.

The LMG2640

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 over-temperature

shut down.