DESCRIPTION

The UTC3843D/E provides the necessary features to

implement off-line or DC to DC fixed frequency current mode

control schemes with a minimal external parts count. Internally

implemented circuits include under-voltage lockout featuring

start up current less than 1mA, a precision reference trimmed

for accuracy at the error amp input, logic to insure latched

operation, a PWM comparator which also provides current limit

control, and a totem pole output stage designed to source or

sink high peak current. The output stage, suitable for driving N

channel MOSFETs, is low in the off state.

FEATURES

*Optimized for off-line and DC to DC converts

*Low start up current(<1mA)

*Automatic feed forward compensation

*Pulse-by-Pulse current limiting

*Enhanced load response characteristics

*Under-voltage lockout with hysteresis

*Double pulse Suppression

*High current totem pole output

Internally trimmed bandgap reference

*500kHz operation

*Low Ro error amp