• Optimized for Off-Line and DC-to-DC Converters

• Low Start-Up Current (< 1 mA)

• Automatic Feed-forward compensation

• Pulse-by-Pulse Current Limiting

• Enhanced Load-Response Characteristics

• Undervoltage Lockout With Hysteresis

• Double-Pulse Suppression

• High-Current Totem-Pole Output

• Internally Trimmed Bandgap Reference

• 500-kHz Operation

• Error Amplifier With Low Output Resistance

• Designed to be Interchangeable with UC2842 and UC3842 Series

The TL284x and TL384x series of control integrated circuits provide the features that are necessary to implement off-line or DC-to-DC fixed-frequency current-mode control schemes, with a minimum number of external components. Some of the internally implemented circuits are an undervoltage lockout (UVLO), featuring a start-up current of less than 1 mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (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 when it is in the off state.