Texas Instruments UCC28730

Description

The UCC28730 isolated-flyback power supply controller provides Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler, and signal detection to improve transient response to large load steps. A minimum switching frequency of 30 Hz facilitates achieving less than 5 mW of no-load power. This device processes information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. The monitoring works with a secondary-side alarm device such as the UCC24650 to deliver rapid response to heavy load steps using minimal output capacitance.An internal 700-V start-up switch, dynamically- controlled operating states and a tailored modulation profile support ultra-low stand-by power without sacrificing start-up time or output transient response. Control algorithms in the UCC28730 allow operating efficiencies to meet or exceed applicable standards. Discontinuous conduction mode (DCM) operation with valley-switching reduces switching losses. Modulation of the switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

Features

• Enables (<5 mW) Standby Consumption
• Smart Detection Enables Smallest Output Capacitance
• Primary-Side Regulation (PSR) Eliminates Opto-coupler
• ±5% Voltage Regulation and Current Regulation Across Line and Load
• 700-V Start-up Switch
• 83-kHz Maximum Switching Frequency Enables Low Stand-by Power Charger Designs
• Resonant-Ring Valley-Switching Operation for Highest Overall Efficiency
• Frequency-Dither to Ease EMI Compliance
• Clamped Gate-Drive Output for MOSFET
• Over-Voltage, Low-Line, and Over-Current Protection Functions
• Programmable Cable Compensation
• SOIC-7 Package

Typical applications

• Standby and Auxiliary Power Supplies
• TV and Monitor Power Supplies
• SMPS for Home Appliances and Industrial Automation
• Adapters and Chargers for Smart Phones, Tablets
• Other Consumer Electronics

More information

• Datasheet
• IC product information