The UCC3895 is a phase-shift PWM controller that implements control of a full-bridge power stage by phase shifting the switching of one half-bridge with respect to the other. It allows constant frequency pulse-width modulation in conjunction with resonant zero-voltage switching to provide high efficiency at high frequencies. The part can be used either as a voltage-mode or current-mode controller.
While the UCC3895 maintains the functionality of the UC3875/6/7/8 family and UC3879, it improves on that controller family with additional features such as enhanced control logic, adaptive delay set, and shutdown capability. Since it is built using the BCDMOS process, it operates with dramatically less supply current than it’s bipolar counterparts. The UCC3895 can operate with a maximum clock frequency of 1 MHz.
• Programmable Output Turn-on Delay
• Adaptive Delay Set
• Bidirectional Oscillator Synchronization
• Voltage-Mode, Peak Current-Mode, or Average Current-Mode Control
• Programmable Softstart/Softstop and Chip Disable via a Single Pin
• 0% to 100% Duty-Cycle Control
• 7-MHz Error Amplifier
• Operation to 1 MHz
• Typical 5-mA Operating Current at 500 kHz
• Very Low 150-μA Current During UVLO
• Phase-Shifted Full-Bridge Converters
• Off-Line, Telecom, Datacom and Servers
• Distributed Power Architecture
• High-Density Power Modules