2.6-A, 110-V half bridge gate driver with enable and interlock

The LM5108 is a high frequency

half-bridge gate driver with maximum switch node (HS) voltage rating of 100 V. It

allows for two N-channel MOSFETs to be controlled in half-bridge configuration based

topologies such as synchronous buck, full bridge, active clamp forward, LLC, and

synchronous boost.

The device has interlock functionality

which, prevents both outputs from being high at the same time, in the case when both

of the inputs are high. This interlock feature improves system robustness in motor

drive and power tools applications. Enable and disable functionality allows for the

flexible and fast control of the power stage. Battery powered tools can also use

enable feature of the LM5108 to reduce the standby current as well as to respond to

system fault. The inputs are independent of supply voltage and can have independent

pulse width. This allows maximum control flexibility. Both inputs and enable have

sufficient hysteresis to improve the system robustness in noise prone applications

such as motor drives.

The low-side and the high-side outputs

are matched to 1-ns between the turn-on and turn-off of each other. This allows for

dead-time optimization which in-turn improves efficiency. 5-V UVLO allows the driver

to operate at lower bias supplies which further allows the power stage to operate at

higher switching frequency without increasing switching losses. VDD and HB UVLO

threshold specifications are designed in such as way that both the high-side and

low-side driver turns on typically at 5 V. If both VDD and HB UVLO thresholds are

the same then designer would need higher bias supply than the VDD UVLO threshold to

turn-on both high-side and low-side driver.

An on-board bootstrap diode eliminates

the need for an external discrete diode which improves board space utilization.

Small package enables dense power designs such as power tools.