Synchronous-Rectified Buck MOSFET Drivers

The RT9618/A are high frequency, dual MOSFET drivers specifically designed to drive two power N-MOSFETs in a synchronous-rectified buck converter topology. The drivers combined with Richtek's series of Multi-Phase Buck PWM controller form a complete core-voltage regulator solution for advanced micro-processors.
The RT9618/A drive both the lower/upper gate in a synchronous-rectifier bridge with 12V. This drive-voltage flexibility provides the advantage of optimizing applications involving trade-offs between switching losses and conduction losses.
RT9618A has longer UGATE/LGATE deadtime which can drive the MOSFETs with large gate RC value, avoiding the shoot-through phenomenon. RT9618 is targeted to drive low gate RC MOSFETs and performs better efficiency.
The output drivers in the RT9618/A can efficiently switch power MOSFETs at frequency up to 500kHz. Switching frequency above 500kHz has to take into account the thermal dissipation of the packages. RT9618/A are capable to drive a 3nF load with a 30ns rise time. RT9618/A implements bootstrapping on the upper gate with an external capacitor and an embedded diode. This reduces implementation complexity and allows the use of higher performance, cost effective N-MOSFETs. Adaptive shoot-through protection is integrated to prevent both MOSFETs from conducting simultaneously.