The UCC3805DTR/81222 is an integrated circuit (IC) component designed for controlling primary-side regulation in offline flyback converters. It is a member of the UCC3805 family of current-mode pulse width modulation (PWM) controllers. The UCC3805DTR/81222 has several key features that make it suitable for various power supply applications.
1. Current-Mode Control: The UCC3805DTR/81222 utilizes current-mode control, which provides excellent system stability and precise output regulation. This control mechanism allows for easy compensation and fast response to load transients, ensuring optimal performance under varying operating conditions.
2. Internal Startup Circuitry: The IC includes an internal high-voltage startup regulator that eliminates the requirement for an additional startup circuit, reducing component count and simplifying the system design. It also provides protection against undervoltage and dropout conditions.
3. Oscillator: The integrated oscillator operates at a fixed frequency, typically 66 kHz, ensuring stable and predictable operation. The frequency remains relatively constant even under varying operating conditions, enabling efficient power delivery.
4. Precision Reference: The UCC3805DTR/81222 incorporates a precision reference voltage source that provides accurate voltage feedback, enabling precise control of the output voltage. This feature ensures the power supply delivers the desired voltage to the load.
5. Advanced Protection Features: The IC offers various protection features to enhance system reliability
