H6842P

HI-SINCERITY MICROELECTRONICS CORP. Spec. No. : IC200803 Issued Date : 2008.09.10 Revised Date : Page No. : 1/6 H6842P / H6842S Novel Low Cost Green-Power PWM Controller Description The H684 2 is a lo w startup cu rrent, lo w co st, curre n. mode PWM co ntroller with Package Code: P Green-Power & burst- mode power-saving operation. The integrated functions such as the leading-edge blanking of the current sensing, internal slope compensation provide the users a high efficiency, low external component counts, and low cost solution for A C/DC po wer app lications. The special Green-Power function provides off-time modulation to linearly decrease the switching frequency under ight-load conditions. And under zero-load conditions, the power supply enters burst-mode to 8-Lead Plastic SO-8 Package Code: S further reduce power consumption b y shutting off P WM output. When the output of power supply is short or over loaded, the FB voltage will increase, and if the FB voltage is higher than 5.2V f or longer th an 56msec the PWM out put will be turned off. A external NTC resi stor connected from pin RT to ground can be applied to over- temperature protection. Pulse by pulse current limit ensures a constant output current even under short circuit. PWM output will be disabled as long as VDD exceeds a threshold. When internal latch circuit is us ed to latch-off the controller the latch wil be reset when the power supply VDD is disabled 8-Lead Plastic DIP-8 Features Low Cost, Gree...