The UCC28070 is an advanced power factor correction device that integrates two pulse-width modulators (PWMs) operating 180° out of phase. This Natural Interleaved PWM operation generates substantial reduction in the input and output ripple currents, and the conducted-EMI filtering becomes easier and less expensive. A significantly improved multiplier design provides a shared current reference to two independent current amplifiers that ensures matched average current mode control in both PWM outputs while maintaining a stable, low-distortion sinusoidal input line current.
The UCC28070 contains multiple innovations including current synthesis and quantized voltage feed-forward to promote performance enhancements in PF, efficiency, THD, and transient response. Features including frequency dithering, clock synchronization, and slew rate enhancement further expand the potential performance enhancements.
The UCC28070 also contains a variety of protection features including output over-voltage detection, programmable peak-current limit, in-rush current detection, under-voltage lockout, and open-loop protection.
- Interleaved Average Current-Mode PWM Control with Inherent Current Matching
- Advanced Current Synthesizer Current Sensing for Superior Efficiency and PF
- Highly-Linear Multiplier Output with Internal Quantized Voltage Feed-Forward Correction for Near-Unity PF
- Programmable Frequency (up to 300 kHz)
- Programmable Maximum Duty-Cycle Clamp
- Programmable Frequency Dithering Rate and Magnitude for Enhanced EMI Reduction
- Magnitude: Up to 30 kHz
- Rate: Up to 30 kHz
- External Clock Synchronization Capability
- Enhanced Load and Line Transient Response through Voltage Amplifier Output Slew-Rate Correction
- Programmable Peak Current Limiting
- Bias-Supply UVLO, Over-Voltage Protection, Open-Loop Detection, and PFC-Enable Monitoring
- External PFC-Disable Interface
- Open-Circuit Protection on VSENSE and VINAC pins
- Programmable Soft Start
- 20-Lead TSSOP Package
- APPLICATIONS
- High-Efficiency Server and Desktop Power Supplies
- Telecom Rectifiers
