AC/DC converters simplify buck converter designs for appliances

Power Integrations has extended its LinkSwitch-TN2 AC/DC converter family with the LNK3207 AC/DC converters. Targeting higher-power offline buck converter designs for appliances and industrial applications, the new AC/DC converters increase the available output current from 360 mA to 575 mA, while also reducing bill-of-materials (BOM) count.

Designed to simplify buck converter designs for appliances and industrial applications, the LinkSwitch-TN2 ICs are pin-to-pin compatible with previous generations to make it easier to upgrade to the higher-power designs, said PI. These devices can be used in appliances such as washers, dryers, and coffee makers, and sensor-based devices that require low power such as home security cameras and smart thermostats, as well as metering and IoT installations.

Key features of the LNK3207 AC/DC converter ICs include a 60% increase in the available current, greater than 80% efficiency, and no-load consumption of less than 30 mW. In addition to integrating a 725-V power MOSFET and oscillator, the devices also include on/off control for high efficiency at light load, a high-voltage switched current source for self-biasing, frequency jittering, fast (cycle-by-cycle) current limit, hysteretic thermal shutdown, and output and input overvoltage protection circuitry.

The LinkSwitch-TN2 ICs are available in three packages – PDIP-8C, SMD-8C and SO-8C. The SMD-8C package is suited for high-temperature ambient 85°C /105°C applications.

The LNK3207 AC/DC converters are priced at $0.60 in volume. A reference design, the RDR-912, for a 6.6-W non-isolated buck converter with a 85 VAC – 265 VAC input and a 12-V, 550-mA output, is available. The devices are available through PI’s authorized worldwide distributors: Digi-Key, Farnell, and Mouser.