Power & Power Management

Overview

The iW1677 is a high-performance AC/DC controller designed to drive a low-cost bipolar junction transistor (BJT) power switch in peak current mode PWM flyback power supplies up to 5W. Ideal for power adapters for smartphones, the iW1677 integrates Renesas' PrimAccurate™ digital primary-side control, eliminating the need for the secondary-side optocoupler, and reducing component count and solution cost.

The iW1677 integrates an active start-up circuit that allows for fast turn-on without impacting operating current consumption. The device easily meets the US DoE’s external power supply standard and the EU’s Code of Conduct, Version 5, Tier 2 standard, with no-load power consumption less than 20mW.  Additional features include Renesas' proprietary EZ-EMI™ technology, quasi-resonant control for optimal efficiency at heavy loads, cable and connector voltage drop compensation options, full protection from fault conditions, and tiny packaging.

  • Meets proposed mandatory federal efficiency standards for external power supplies
  • Intrinsically low noise solution - No audible noise over entire operating range
  • Easily meets Energy Star® AC/DC power supply efficiency specs (Rev. 2.0)
    • Less than 20mW no-load power consumption
  • Low 1.7µA start-up current
  • Active start-up circuit to reduce turn-on time
  • 72kHz PWM switching frequency
  • Voltage offset compensation for voltage loss in cables and connectors (4 options)
  • PrimAccurate™ - Primary-side control, no optocoupler needed
  • Quasi-resonant control for optimal efficiency
  • EZ-EMI™ design to easily meet global EMI specifications
  • Fast dynamic load regulation
  • Fully protected from fault conditions
    • Over-temperature protection
    • Output overvoltage and overcurrent
    • Input undervoltage protection
    • Sense-resistor short circuit protection
  • Power adapters for portable electronics
  • Consumer electronics power supplies
  • Linear AC/DC power supply replacement

Documentation

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