Energy-Efficient ICs Help Create Compact Supplies

The TinySwitch family of off-line switch ICs is the ticket to a new class of compact, energy-efficient power supplies, it's claimed. The chips incorporate the company's EcoSmart technology, which is said to dramatically reduce the load's energy consumption at light or no-load conditions. A TinySwitch-based power supply will draw less than 100 mW in a no-load condition, while typical ac wall adapters consume 10x to 20x more energy, it's asserted.The ICs integrate a 700V power MOSFET, oscillator, high-voltage switched current source, and current limit and thermal shutdown circuitry. They start up and run on power derived from the drain voltage, which eliminates the need for a transformer bias winding and associated circuitry. A simple on/off control scheme also eliminates the need for loop compensation. Reference design boards and application notes, among other design aids, are available.