The RT9618/A is a high frequency, dual MOSFET driver
specifically designed to drive two power N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. This driver combined with Richtek’ s series of
Multi-Phase Buck PWM controller form a complete corevoltage
regulator solution for advanced micro-processors.
The RT9618/A drives 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 SOP-8 package. RT9618/A is
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-Channel MOSFETs. Adaptive
shoot-through protection is integrated to prevent both
MOSFETs from conducting simultaneously.