LD7771TCritical Mode PFC + Current Mode Half-bridge LLC Resonant PWM Controller
LD7771/F/T are PFC and half-bridge LLC resonant combo controllers designed for high efficiency power supplies. By the use of HWC (Hardware Code), LD7771/F/T offers more than 30 configurable parameters to meet the various power supply needs.
The PFC stage features critical mode control, the MOSFET drain voltage is detected by PFCS pin and used as the ZCD signal so the auxiliary winding is saved. The frequency limit curve, soft start, protection level, and feedback compensation are configurable.
The LLC stage regulates the output voltage by controlling resonant capacitor voltage. The feedback compensation, burst parameters, soft start, protection mode and level are configurable.
LD7771/F/T also integrates HV start-up, X-CAP discharge, AC protection and AC compensation; most of their parameters are configurable by the users. In addition, LD7771F also features external OTP while LD7771T features power good signal.
LD7771 is available in a SOP-16 package, while LD7771F/T are available in a TSSOP-20/SOP-20 package.
Features
- High performance digital PFC+LLC controller
- HV X-CAP. discharge
- Low THD with AC compensation
- Critical mode PFC without auxiliary winding
- Current mode like control LLC
- Low standby input power
- Configurable functions and parameters
- Power Good Signal (LD7771T only)
- Protection:
- AC brown in/out
- PFC stage OCP/DSCP/1st, 2nd OVP
- LLC stage SCP/OCP/OLP/CMR
- Output SCP/OCP/OVP
- Output UVP(LD7771 only)
- Internal OTP
- External OTP (LD7771F only)
Applications
- TV Power Supply
- Monitor Power Supply
- Adaptor
- Networking
