UC3842AN

Product Summary

The UC3842AN high performance fixed frequency current mode controller is specifically designed for off-line and DC-to-DC converter applications offering the designer a cost effective solution with minimal external components. The UC3842AN features a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.

Parametrics

UC3842AN maximum ratings: (1)Bias and Driver Voltages (Zero Series Impedance, see also Total Device spec), VCC, VC: 30 V; (2)Total Power Supply and Zener Current, (ICC + IZ): 30 mA; (3)Output Current, Source or Sink, IO: 1.0 A; (4)Output Energy (Capacitive Load per Cycle), W: 5.0 uJ; (5)Current Sense and Voltage Feedback Inputs, Vin: -0.3 to + 5.5 V; (6)Error Amp Output Sink Current, IO: 10 mA; (7)Power Dissipation and Thermal Characteristics: D Suffix, Plastic Package: Maximum Power Dissipation @ TA = 25℃: PD=862 mW; Thermal Resistance, Junction.to.Air: RθJA=145℃/W; N Suffix, Plastic Package: maximum Power Dissipation @ TA = 25℃: PD=1.25 W; Thermal Resistance, Junction.to.Air: RθJA=100℃/W; (8)Operating Junction Temperature, TJ: + 150 ℃; (9)Operating Ambient Temperature, TA: 0 to + 70℃; (10)Storage Temperature Range, Tstg: -65 to + 150 ℃.

Features

UC3842AN features: (1)Trimmed Oscillator Discharge Current for Precise Duty Cycle Control; (2)Current Mode Operation to 500 kHz; (3)Automatic Feed Forward Compensation; (4)Latching PWM for Cycle-By-Cycle Current Limiting; (5)Internally Trimmed Reference with Undervoltage Lockout; (6)High Current Totem Pole Output; (7)Undervoltage Lockout with Hysteresis; (8)Low Startup and Operating Current; (9)Direct Interface with ON Semiconductor SENSEFET Products; (10)Pb-Free Packages are Available.

Diagrams