100W no-Opto Isolated Flyback Controller Operates from 16V to 600V

Analog Devices LT8316


Analog Devices/Powered by Linear introduced a high-voltage flyback controller that does not need an optoisolator for regulation.

The LT8316 samples the output voltage from the isolated flyback waveform appearing across a third winding on the transformer.

Analog Devices - LT8316

Typical applications for the controller include isolated telecom, automotive, industrial, and medical power supplies; isolated off-line housekeeping power supplies; electric vehicles and battery stacks; and multioutput isolated power supplies for inverter gate drives.

Quasi-resonant boundary mode operation enhances load regulation, reduces transformer size, and helps maintains high efficiency.

At start-up, a high voltage current source charges the LT8316’s INTVCC capacitor. During regular operation, the current source turns off, and the device draws power from a third winding on the transformer, minimizing standby power dissipation.

The LT8316 operates from a wide range of input supply voltages from 16 V to 600 V and can deliver up to 100 W of power. It is available in a thermally enhanced 20-pin TSSOP package with four pins removed for high-voltage spacing.

LT8316 features Quasi-Resonant Boundary Mode as well as Low-Ripple Light Load Burst Mode® operation. It offers soft-start and a programmable current limit. The flyback controller also has a low quiescent current of 75 µA.

Efficiency vs. Load Current
Efficiency vs. Load Current.


  • Wide Input Voltage Range: 16 V to 600 V
  • Delivers up to 100 W of power
  • No Opto-Isolator Required for Regulation
  • Quasi-Resonant Boundary Mode Operation
  • Constant-Current and Constant-Voltage Regulation
  • Low-Ripple Light Load Burst Mode Operation
  • Low Quiescent Current: 75 µA
  • Programmable Current Limit and Soft-Start
  • TSSOP Package with High-Voltage Spacing


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