New Industry Products

Constant Voltage Flyback IC with Secondary Side Regulation for LED Drivers

March 21, 2019 by Scott McMahan

Infineon Technologies AG introduced the new member of its XDP™ LED controller series, the digital and highly integrated XDPL8218 for cost-effective LED drivers. The device combines a constant voltage quasi-resonant flyback controller with algorithms for high power factor (>0.9) and low total harmonic distortion (<15%). The XDPL8218 is suitable for the primary side of dual-stage LED designs with a dc-dc stage at the secondary.

The flyback IC can be used in LED drivers with constant voltage secondary side regulation. (See typical application diagram above).

The company says that the device manages wide load ranges, responds quickly and stably to dynamic load changes, and enables high efficiency over a wide output range. The new LED driver IC supports full functionality for both ac and dc input in the nominal input voltage range of 100Vac to 277Vac or 127Vdc to 430Vdc.

A built-in digital control automatically selects the optimal operation mode for the actual operating condition, such as quasi-resonant, discontinuous conduction, or active burst modes.The XDPL8218 fits well with linear driver ICs such as the BCR601 from Infineon that offer voltage feedback to the primary side, helping to reduce power losses in the pass-transistor. The XDPL8218 supports the design of high performance and innovative LED drivers. The digital parameter configuration enables real-time design changes with little effort shortening design cycles and reducing time-to-market.

XDPL8218 constant voltage flyback IC for LED drivers with secondary side regulation

Moreover, the compact bill of materials minimizes system costs and allows for increased flexibility. Since the device can be used for multiple board variants, the number of stock keeping units is reduced considerably.

A comprehensive and configurable set of protection features ensures high reliability and long lifespan of the flyback IC. For adverse operating conditions and unstable grids, the configurable brownout and -in function is built-in. All relevant potential error conditions are monitored and protected, including under- and over-voltage for input and output, open load and output shorted. An adaptive temperature guard also ensures optimal thermal management.

Infineon offers a user-friendly GUI for PCs, allowing rapid engineering changes including changes in protection feature configurations without the need for complex component design iterations. Functionality can be defined at the end of the production line. Multiple different power supplies can be built with the same hardware using different XDPL8218 parameter sets.


  • Programmable constant voltage output with secondary side regulation
  • Supports AC and DC input
  • Nominal input voltage range 100Vac to 277Vac or 127Vdc to 430Vdc
  • Reference board efficiency >90%
  • Power factor >0.9 and THD <15% over wide load range
  • Standby power <100mW
  • Temperature guard with adaptive thermal management with on-chip sensor
  • Digital control selects automatically best mode of operation, depending on actual requirements
    • QRM (Quasi resonant mode)
    • DCM (Discontinuous conduction mode)
    • ABM (Active burst mode)
  • Tunable, digital parameters
  • Configurable brown-out and brown-in protections
  • Embedded digital filters
  • Relevant error conditions are monitored and protected
    • Under-voltage
    • Over-voltage
    • Open load
    • Output shorted


  • The XDPL8218 enables the design of high performance and innovative value LED driver with small effort
  • Reduced BoM minimizes system cost and increases flexibility
  • High-reliability features improve lifetime of the driver
  • Fast design cycles reduce time to market and efforts for value products
  • Supply chain efficiency optimizes stock keeping and enables high flexibility