TNY268 Power Integrations Off-line Switcher IC

Description

The TNY268 integrates a 700 V power MOSFET, oscillator, high voltage switched current source, current limit, and thermal shutdown circuitry onto a monolithic device IC. The start-up and operating power are derived directly from the voltage on the DRAIN pin, eliminating the need for a bias winding and associated circuitry. In addition, the TNY268 device incorporates auto-restart, line under-voltage sense, and frequency jittering. An innovative design minimizes audio frequency components in the simple ON/OFF control scheme to practically eliminate audible noise with standard taped/varnished transformer construction.
The fully integrated auto-restart circuit safely limits output power during fault conditions such as output short circuit or open loop, reducing component count and secondary feedback circuitry cost. An optional line sense resistor externally programs a line undervoltage threshold, which eliminates power down glitches caused by the slow discharge of input storage capacitors present in applications such as standby supplies. The operating frequency of 132 kHz is jittered to significantly reduce both the quasi-peak and average EMI, minimizing filtering cost.

Pinout 

1	BYPASS (BP)
2	SOURCE (S)
3	SOURCE (S)
4	ENABLE UNDERVOLTAGE (EN/UN)
5	DRAIN (D)
7	SOURCE (HV RTN)
8	SOURCE (HV RTN)

Features

• Built-in circuitry practically eliminates audible noise with ordinary dip-varnished transformer
• Programmable line undervoltage detect feature prevents power on/off glitches
• Very tight tolerances and negligible temperature variation on key parameters eases design and lowers cost
• 132 kHz frequency reduces transformer/power supply size
• Hysteretic thermal shutdown for automatic fault recovery
• Large thermal hysteresis prevents PC board overheating 

For more information refer to Datasheet

Specifications

Model	TNY268
230 VAC ± 15% Adapter Open Frame	16W 23W
85-265 VAC Adapter Open Frame	10W 15W
Drain Voltage	-0.3V to 700V
Drain Peak Current	880mA
EN/UV Voltage	-0.3V to 9V
EN/UV Current	100 mA
BYPASS Voltage	-0.3V to 9V
Storage Temperature	-65 °C to 150 °C
Operating Junction Temperature	-40 °C to 150 °C
Switching Frequency	132 kHz