TNY256PN Off-line Switcher IC

TinySwitch family introduced by Power Integrations designed as the latest generation of its industry-leading TinySwitch series of off-line switcher ICs.  It is basically a complete integrated circuit with all functionalities at a low cost, with high efficiency, off-line switcher solution in the 0 to 10W range.

The TNY256PN incorporates a 700 V power MOSFET, oscillator, high voltage switched current source, current limit (user selectable) and thermal shutdown circuitry into a single monolithic device.  Thus offers a design flexible solution with a low system cost and extended power capability. Unlike conventional PWM (pulse width modulator) controllers, it uses a simple ON/OFF control to regulate the output voltage. They initiate its operation and run on the power derived from the DRAIN voltage. Thereby eliminating the need for a transformer bias winding and the associated circuitry. Hence, it consume only about 100 mW at no load, from 265 VAC input.

TinySwitch-II features auto-restart, line undervoltage sense, and frequency jittering. These IC family uses an ON/OFF control scheme also eliminates the audible noise with standard taped/varnished transformer construction. The fully integrated auto-restart circuit ensures safely limits output power during fault conditions such as output short circuit/open loop. Thereby reducing component count and secondary feedback circuitry cost. The power-down glitches caused by the slow discharge of input storage capacitors present in applications such as standby supplies eliminated via n optional line sense resistor externally programs a line undervoltage threshold. The operating frequency of 132 kHz jittered to significantly reduce both the quasi-peak and average EMI, minimizing filtering cost.

Applications

• Chargers/adapters for cell/cordless phones, PDAs, digital
• Cameras, MP3/portable audio, shavers, etc.
• PC Standby and other auxiliary supplies
• Supplies for appliances, industrial systems, metering, etc.