15-W Dual Output Isolated Bias AC-DC with 4-mW Standby – Reference Design

August 29, 2018 by Paul Shepard

The TIDA-01560 reference design from Texas Instruments is a 15-W bias power supply with two isolated outputs (12 V/1.125A and 3.3 V/0.3A) and a total standby power consumption of 4mW under a 220-Vac input. The controller uses primary-side regulation (PSR) and detects a wake-up signal from the UCC24650 secondary-side voltage-droop monitor for improved transient response to large load steps.

Anticipated applications include washing machines, coffee machines, cooking ranges, small home appliances, disinfection cabinets, toilet seat covers, TV and monitor power supplies, and so on.

This reference design demonstrates how the UCC28730 can provide ultra-low standby power without sacrificing start-up time or output transient response with an internal 700-V start-up switch, dynamically controlled operating states, and a tailored modulation profile.

The UCC28730 uses frequency modulation, peak primary current modulation, valley switching, and valley skipping in its control algorithm to maximize efficiency over the entire operating range.

Summary of features:

  • Enables Zero-Power Standby Consumption, 3.1mW at 115-Vac Input and 4.2mW at 220-Vac Input
  • Average Efficiency > 84%, Exceeds DoE VI and CoC Tier 2 Specifications
  • Primary-Side Regulation (PSR) Eliminates Optocoupler and Increase Reliability of Bias Power Supply
  • Resonant-Ring Valley-Switching Operation for Highest Overall Efficiency
  • Universal Input Voltage Range (85- to 270-VacC) to Address Customer Needs Across All Regions
  • Dual Isolated Outputs of 12 V and 3.3 V is Suitable for Most Industry Applications
  • Frequency-Dither to Ease EMI Compliance
  • Full Protection With Overvoltage, Low-Line, and Overcurrent Functions

TIDA-01560 15W Dual Isolated Output Bias Power Supply with 4mW Zero Standby Power Consumption Reference Design Board