Current Mode PWM Controller 1A 8-Pin SOIC T/R

The UC3843A series of high performance fixed frequency current mode controllers are specifically designed for off-line and DC-to-DC converter applications offering the designer a cost effective solution with minimal external components. These integrated circuits feature 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. These devices are available in an 8-pin dual-in-line plastic package as well as the 14-pin plastic surface mount (SOIC-14). The SOIC-14 package has separate power and ground pins for the totem pole output stage. The UC3843A is tailored for lower voltage applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off).

• 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 SENSEFET™ Products