TOPSwitch-GX uses the same proven topology as TOPSwitch,cost effectively integrating the high voltage power MOSFET,PWM control, fault protection and other control circuitry ontoa single CMOS chip. Many new functions are integrated toreduce system cost and improve design flexibility, performanceand energy efficiency.Depending on package type, either 1 or 3 additional pins overthe TOPSwitch standard DRAIN, SOURCE and CONTROLterminals allow the following functions: line sensing (OV/UV,line feed-forward/DCMAX reduction), accurate externally setcurrent limit, remote ON/OFF, synchronization to an externallower frequency, and frequency selection (132 kHz/66 kHz).All package types provide the following transparent features:Soft-start, 132 kHz switching frequency (automatically reducedat light load), frequency jittering for lower EMI, wider DCMAX,hysteretic thermal shutdown, and larger creepage packages. Inaddition, all critical parameters (i.e. current limit, frequency,PWM gain) have tighter temperature and absolute tolerancesto simplify design and optimize system cost.