Converter Offline Flyback Topology 32Hz ~ 83kHz 7-SOIC
Controller 9V to 35V 7-Pin SOIC Tube
Feature
- Enables Zero-Power (<5 mW) standbyconsumption
- Smart Wake-Up detection enablessmallest output capacitance
- Primary-side regulation (PSR) eliminatesoptocoupler
- ±5% voltage regulation and current regulation across line andload
- 700-V start-up switch
- 83-kHz maximum switchingfrequency enables low stand-by power charger designs
- Resonant-ringvalley-switching operation for highest overall efficiency
- Frequency-dither toease EMI compliance
- Clamped gate-drive output forMOSFET
- Overvoltage, low-line, and overcurrent protectionfunctions
- Programmable cable compensation
- SOIC-7package
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DescriptionThe UCC28730 isolated-flyback power supply controller provides Constant-Voltage (CV) andConstant-Current (CC) output regulation without the use of an optical coupler, andwake-up signal detection to improve transient response to largeload steps. A minimum switching frequency of 30 Hz facilitates achieving less than 5 mW of no-loadpower. This device processes information from the primary power switch and an auxiliary flybackwinding for precise control of output voltage and current. The wake-up monitoring works with a secondary-side alarm device such as theUCC24650 to deliver rapid response to heavy load steps using minimal output capacitance.
An internal 700-V start-up switch, dynamically- controlled operating states and atailored modulation profile support ultra-low stand-by power without sacrificing start-up time oroutput transient response. Control algorithms in the UCC28730 allow operating efficiencies to meetor exceed applicable standards. Discontinuous conduction mode (DCM) operation with valley-switchingreduces 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.
