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.
● 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
