TheUC3845BN is of control ICs 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 0.5 A.

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 offstate.

UC3845BN Features:

• Trimmed Oscillator for Precise frequency Control
• Oscillator Frequency Guaranteed at 250 Hz
• Current Mode Operation to 500 kHz
• Automatic Feed Forward Copensation
• Latching PWM for Cycle-by-cycle Current Limiting
• Internally Trimmed Reference with Undervoltage lockout
• High Current totem pole output Undervoltage Lockout With Hystersis
• Low Start-up and Operating Current