UC3844BD1

UC3844BD1 is a high-performance current mode PWM controller. This control IC provides the necessary features to implement offline 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 a start-up current less than 0.5mA, a precision reference trimmed for accuracy at the error amp input, logic to ensure latched operation, a PWM comparator that 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 offstate. Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges.

• Trimmed oscillator for precise frequency control
• Oscillator frequency guaranteed at 250KHz
• Current mode operation to 500KHz
• Automatic feed-forward compensation, low start-up and operating current
• Latching PWM for cycle-by-cycle current limiting
• Internally trimmed reference with undervoltage lockout
• High current totem pole output
• Undervoltage lockout with hysteresis
• SO8 package, -40 to 150°C junction operating temperature
• Supply voltage (low impedance source) is 30V, ±1A output current