DESCRIPTION

The UTC3842 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 band-gap reference

*500kHz operation

*Low Ro error amp