Off-Line Controllers with Integrated FET Deliver up to 48W

The new STR3A400HDL series from Sanken are power ICs for switching power supplies, incorporating a 700V MOSFET and a current-mode pwm controller IC. They are designed for use in ac-dc adapters, white goods and other applications needing low-noise, high-efficiency ac-dc power conversion.

Operational details including a detailed reference design are included in the Data Sheet.

The low standby power is accomplished by the automatic switching between pwm operation in normal operation and the burst-oscillation under light load conditions. The product achieves high cost-performance power supply systems with few external components.

Reference Design from Data Sheet (click on image to enlarge)

These ICs include a variety of protection functions including two types of overcurrent protection (OCP); Pulse-by-Pulse, and a built-in compensation circuit to minimize OCP point variation on ac input voltage.

In addition the STR3A400HDL includes overload protection with automatic restart, overvoltage protection with automatic restart and thermal shutdown with auto-restart with hysteresis.

Features include:

  • Low Thermal Resistance Package
  • Improving circuit efficiency (Since the step drive control can keep VRM of secondary rectification diodes low, the circuit efficiency can be improved by low VF)
  • Noise Reduction
  • Current Mode Type PWM Control
  • Soft Start Function
  • Automatic Standby Function
  • No Load Power Consumption < 15mW
  • Operation Mode
    • Normal Operation in PWM Mode
    • Light Load Operation in Sanken Green-Mode
    • Standby in Burst Oscillation Mode
  • Random Switching Function
  • Slope Compensation Function
  • Leading Edge Blanking Function
  • Bias Assist Function

(click on image to enlarge)

Sanken Electric Co. Ltd.
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