TIUC3842AD8TR
Overview
The UC3842AD8TR is a high-performance fixed-frequency current-mode PWM controller designed for off-line and DC-DC converter applications. It provides the necessary features to implement control of various topologies including flyback, forward, buck, and boost converters with minimal external components. This device features a high-current totem pole output stage suitable for driving power MOSFETs and includes integrated undervoltage lockout with hysteresis.
Why Choose This Part
The controller offers a high-current totem pole output capable of sourcing and sinking up to 1A peak, which simplifies MOSFET gate drive circuitry. Its current-mode architecture provides inherent pulse-by-pulse current limiting and improved load-response characteristics compared to voltage-mode controllers. Additionally, the low start-up current of less than 0.5mA reduces power dissipation in the startup resistor for high-voltage applications.
Applications
Key Specifications
Getting Started
To begin design, calculate the timing resistor and capacitor values for the desired switching frequency up to 500kHz. Ensure the VDD supply includes a bypass capacitor placed close to the IC pins to handle high-current switching transients from the totem pole output. Review the undervoltage lockout thresholds in the datasheet to properly size the startup resistor for off-line applications.
