The LMS1225 is a low-side integrated device with a 22.5V FET and a high-performance driver for secondary-side synchronous rectification with body-diode conduction sensing. The device is designed for high-power high-efficiency center-tapped LLC converter applications where dead-time optimization is desired. The body-diode conduction is sensed and a pulse is sent to the a digital-power controller through one digital IO pin. The digital controller can adjust the dead-time setting based on this information. At the turn-on edge, in the IDM mode, the gate driver in theLMS1225 optimizes the dead time by turning the gate on when the diode conduction is detected. The benefits of this driver to the system include, but are not limited to, improved efficiency, improved reliability, and ease of design.

The internal gate driver is a single-channel, high-speed gate driver designed for a 5V drive. The package and pin configuration provide minimum parasitic inductances to reduce rise and fall times and to limit ringing. Additionally, the short propagation delay with minimized tolerances and variations allows efficient operation at high frequencies.

The internal body-diode conduction detector is a high-speed comparator with 4ns propagation delay. The DTC output is internally pulled high by default. When sensing a body-diode conduction, the DTC pin drives low.