illustrate

The combined PFC/PWM controller of the UCC28521 with the UCC28528 provides complete control functionality for any offline power supply required with IEC1000-3-2 harmonic requirements reduced system. By combining the control and drive signals of PFC and PWM stages into a single device, significant performance and cost advantages are beneficial.

Based on the UCC28511, an average current-mode control architecture for input voltage feed-forward of the new device is adopted. The main difference between the UCC28521/28 is the trailing/trailing edge (TEM/TEM) as the circuit/PWM stage modulation scheme. The UCC28528 PWM segment is different as it drops the UCC28521 with a non-turn bulk voltage. The UCC28528 PWM is an aid for low-power design.

characteristic

• The PFC and PWM power stages are controlled in one device
• PFC of trailing edge, trailing edge PWM modulation
• Built-in PFC and PWM sequencing turned up
• 2, Source and 3 Sink are suitable for PFC and PWM gate drive in both stages
• A typical rise time of 16 - ns and a fall time of 7 ns are 1 - NF load
• Features of PFC
  • Continuous conduction mode operation for average current mode control
  • High linear multiplier has a power factor of nearly 1
  • Input voltage feed-forward implementation
  • Improved load transient response
  • Precise power limiting
  • Zero power detection
• Features of PWM
  • Peak current mode control operation
  • 1:1 PFC: Pulse width modulation frequency option
  • Programmable maximum duty cycle limit up to 90%
  • Programmable soft-start
• apply
  • Efficient server and desktop supplies
  • AC-DC converters for efficient telecommunications