描述 Description

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 onto a single CMOS chip. Many new functions are integrated to

reduce system cost and improve design flexibility, performance and energy efficiency. Depending on package type, the TOPSwitch-GX family has either 1 or 3 additional pins over the standard DRAIN, SOURCE and CONTROL terminals. allowing the following functions: line sensing (OV/UV, line feedforward/DC max reduction), accurate externally set current limit, remote on/off, and synchronization to an external lower frequency and frequency selection (132 kHz/66 kHz).

Lower System Cost, High Design Flexibility

? Extended power range to 250 W

? Features eliminate or reduce cost of external components

? Fully integrated soft-start for minimum stress/overshoot

? Externally programmable accurate current limit

? Wider duty cycle for more power, smaller input capacitor

? Separate line sense and current limit pins on Y/R packages

? Line under-voltage (UV) detection: no turn off glitches

? Line overvoltage (OV) shutdown extends line surge limit

? Line feed forward with maximum duty cycle (DCMAX) reduction rejects line ripple and limits DCMAX at high line

? Frequency jittering reduces EMI and EMI filtering costs

? Regulates to zero load without dummy loading

? 132 kHz frequency reduces transformer/power supply size

? Half frequency option in Y/R packages for video applications

? Hysteretic thermal shutdown for automatic fault recovery

? Large thermal hysteresis prevents PC board overheating