UC3843AN Description

The UC3842A and UC3843A series of high-performance fixed frequency current mode controllers are intended primarily for off-line and DC-to-DC converter applications, providing a cost-effective solution with few external components to the designer. A trimmed oscillator for precise duty cycle management, a temperature corrected reference, a high gain error amplifier, a current detecting comparator, and a high current totem pole output well suited for feeding a power MOSFET are all included in these integrated circuits.

Input and reference Undervoltage lockouts with hysteresis, cycle by cycle current limiting, programmable output deadtime, and a latch for single pulse metering are also provided as safety measures. The UC3843AN is offered in both an 8pin dual-inline and a 14pin plastic surface mount (SOIC14) packaging.

UC3843AN Features

• Trimmed Oscillator Discharge Current for Precise Duty Cycle Control

• Current Mode Operation to 500 kHz

• Automatic Feed Forward Compensation

• Latching PWM for Cycle?By?Cycle Current Limiting

• Internally Trimmed Reference with Undervoltage Lockout

• High Current Totem Pole Output

• Undervoltage Lockout with Hysteresis

• Low Startup and Operating Current

• Direct Interface with ON Semiconductor SENSEFET? Products

• Pb?Free Packages are Available

UC3843AN Applications

• General-purpose amplifier

• Switching applications

• Power management

• Industrial