Texas Instruments UCG2883x/4x Self-Biased QR Flyback Converters
Texas Instruments UCG2883x/4x Self-Biased QR Flyback Converters are high-frequency, quasi-resonant flyback converters with an integrated 750V GaN high-electron-mobility transistor for AC/DC power conversion. The devices are developed for high-power-density applications, including fast chargers, notebook adapters, USB-PD adapters, and compact offline power supplies.
The TI UCG2883x/4x converters use a self-bias and auxless-sensing architecture that eliminates the need for an auxiliary winding, helping simplify system design and improve efficiency. The UCG2883x/4x Flyback Converters also support dynamic CCM, QR, and DCM mode transitions, frequency foldback, burst mode, valley locking, and frequency dithering. Furthermore, a slew-rate control is offered for efficient, low-EMI operation across a wide power range.
The converters include merged sensing, high-voltage startup, X-cap discharge, and a broad set of protection features to help improve system reliability. The UCG28836 and UCG28846 are available in 12-pin QFN and 16-pin SOIC packages, with external resistor configurability, enabling flexible platform designs with a single device family.
Features
- Integrated 750V GaN HEMT for AC/DC flyback power conversion
- Dynamic QR, DCM, and CCM modes of operation
- High power density with switching frequency of up to 500kHz
- Self-bias architecture that removes the auxiliary winding
- Integrated input voltage, output voltage, and current sensing
- Integrated high-voltage startup and X-cap discharge
- Efficiency and EMI optimization
- Standby power consumption of less than 30mW
- Frequency foldback and burst mode
- Valley locking and valley hopping
- Frequency dithering and switching slew-rate control
- Comprehensive protection features
- Overtemperature protection
- Input and output overvoltage protection
- Short-circuit protection
- Cycle-by-cycle current limit
- Two-level over-power protection with LPS
- Brown-in and brown-out protection
- Open feedback protection
- External-resistor configurability for X-cap discharge, CCM mode disable, switching slew rate, clamping frequency, fault response, and peak-current ratio settings
Applications
- USB-PD adapter for portable electronics
- USB wall outlets and docking stations
- Industrial DIN rail power supplies
- Server aux power supplies
Specifications
- Flyback topology with peak-current-mode control
- Integrated-switch converter type
- Typical switch current limit of 3.5A
- Operating temperature range of -40°C to +105°C
- Package options
- UCG28836/46 REZ 12-pin QFN package, 5mm x 5mm
- UCG28836/46 D 16-pin SOIC package, 3.9mm x 9.9mm
Associated Converters
Texas Instruments UCG2882x High Frequency QR Flyback Converters
Designed for high power density applications, such as cell phone fast chargers & notebook adapters.
Simplified Schematic
