UC3842 Application Note

●The UC3842BN is a high performance current mode PWM Controller IC 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 a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, 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.

● Trimmed oscillator for precise frequency control

● Oscillator frequency guaranteed at 250kHz

● Current mode operation to 500kHz

● Automatic feed forward compensation

● Latching PWM for cycle-by-cycle current limiting

● Internally trimmed reference with under-voltage lockout

● High current totem pole output

● Under voltage lockout with hysteresis

● Low start-up and operating current