Second-generation, off-line buck switcher IC can withstand mains supply fluctuations

It is designed for non-isolated applications with up to 360mA output current. Like the earlier LinkSwitch-TN, it offers high accuracy, high efficiency and good no-load performance, but with new safety features, such as input and output over-voltage protection and a MOSFET with a 725V breakdown voltage, allowing it to withstand 1kV differential line surges without additional surge suppressors.

It offers robust output short-circuit and over-temperature protection against line surges and swells. Applications include appliances, HVAC, industrial, home automation , IoT and metering systems, particularly, says Andrew Smith, director of training, Power Integrations, for systems for use in regions where power grid stablity is "more challenging".

The IC has a  voltage regulation of better than -/+ 3%. This level of accuracy allows designers to eliminate post regulators, to minimise both bill of materials and size, while increasing efficiency, says Smith. It requires just 20 additional components to complete a buck converter, and may be configured to use off-the-shelf inductors, which further reduces cost and supply chain complexity.

The devices are efficient in low-power applications, for example above 80% in 12V, 120mA (1.4W) buck designs. Designs typically provide efficiency across the entire load range while consuming less than 30mW no-load in a buck arrangement, and less than 10mW when configured as a non-isolated flyback.

This configuration flexibility enables manufacturers to design power supplies to meet worldwide product energy-efficiency requirements, from the ErP Ecodesign Directive, to the California Energy Commission, and Energy Star.

A selectable, cycle-by-cycle current limit allows designers to choose low-cost inductors and capacitors instead of custom wound capacitors, for example, or to configure the circuit to output higher power using optimised external components. T

Three package options are available: PDIP-8C, SO-8C, and SMD-8C.