Overview
The UCC256402ADDBR from Texas Instruments is a fully featured LLC (LLC - Line Load Control) resonant controller designed for use in AC/DC power supplies. This device is part of the UCC25640x family and is optimized for low power mode and burst mode operation, minimizing audible noise and standby power consumption. It is intended to work in conjunction with PFC (Power Factor Correction) controllers to provide a complete power system with minimal external components. The UCC256402ADDBR is particularly suited for applications requiring high efficiency, low noise, and robust transient response.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Input Voltage (HV, HB) | -0.3 | 700 | V | |
| Input Voltage (VCC) | -0.55 | 30 | V | |
| Operating Temperature | -40 | 125 | °C | |
| Quiescent Current (HB - HS) | 42 | 62 | 80 | µA |
| High-Voltage Startup JFET | Yes (for UCC256402 and UCC256404) | |||
| Active X-Capacitor Discharge | Yes (for UCC256404) | |||
| Package | SOIC (9.9 mm x 3.9 mm) |
Key Features
- Optimized low power mode and burst mode algorithm with soft-on and soft-off periods to minimize audible noise at standby operation.
- Hybrid Hysteretic Control (HHC) for excellent line and load transient response.
- Integrated high-voltage gate driver capable of directly driving N-channel MOSFETs in an LLC power stage.
- Programmable burst mode threshold and hysteresis for optimizing efficiency and burst mode operation.
- Automatic dead-time adjustment for gate signals based on half-bridge switch node monitoring.
- Slew rate detector for adaptive dead-time with improved sensitivity.
- Active X-capacitor discharge feature (for UCC256404) to discharge remaining voltage on EMC filter X-capacitors after AC input is unplugged.
Applications
The UCC256402ADDBR is suitable for a variety of applications, including:
- Large screen televisions
- AC-DC adapters
- Industrial power supplies
- LED drivers
These applications benefit from the device's high efficiency, low standby power consumption, and minimal audible noise.
Q & A
- What is the primary function of the UCC256402ADDBR?
The UCC256402ADDBR is a fully featured LLC resonant controller designed for use in AC/DC power supplies, particularly to work with PFC controllers. - How does the UCC256402ADDBR minimize audible noise?
The device uses an optimized burst mode with soft-on and soft-off periods to minimize audible noise during standby operation. - What control algorithm does the UCC256402ADDBR use?
The UCC256402ADDBR uses Hybrid Hysteretic Control (HHC) for excellent line and load transient response. - Can the UCC256402ADDBR drive N-channel MOSFETs directly?
Yes, the UCC256402ADDBR includes integrated high-voltage gate drivers capable of directly driving N-channel MOSFETs in an LLC power stage. - What is the purpose of the active X-capacitor discharge feature?
The active X-capacitor discharge feature (available in UCC256404) discharges the remaining voltage on the X-capacitor of the EMC filters after the AC input is unplugged. - How is the dead-time for gate signals adjusted in the UCC256402ADDBR?
The dead-time is automatically adjusted based on the monitoring of the half-bridge switch node. - What are some common applications for the UCC256402ADDBR?
Common applications include large screen televisions, AC-DC adapters, industrial power supplies, and LED drivers. - What is the operating temperature range for the UCC256402ADDBR?
The operating temperature range is -40°C to 125°C. - Does the UCC256402ADDBR include a high-voltage startup JFET?
Yes, the UCC256402 and UCC256404 include a high-voltage startup JFET. - How is the burst mode threshold programmed in the UCC256402ADDBR?
The burst mode threshold is programmed through the LL/SS pin.
