San Jose, Calif.—Power Integrations Linkswitch-LP family, using very few external components, is designed to replace unregulated (linear) transformer-based battery chargers delivering up to three watts for cell phones, cordless phones, portable audio players, shavers, and other personal electronics.
"Recent energy-efficiency standards practically eliminate the use of linear-transformer-based external power supplies in key markets such as California," noted Doug Bailey, vice president of marketing. "LinkSwitch-LP is ideal for designers whose mandate is to meet these standards at the lowest possible cost. Chargers using LinkSwitch-LP are vastly simpler than discrete designs, which typically contain dozens of components,” Bailey continued. “LinkSwitch-LP also offers integrated energy-efficiency and safety features that are either unavailable in discrete designs or, at best, require additional components and design effort."
LinkSwitch-LP features a 700-volt power MOSFET integrated with control and fault protection circuitry. The IC operates across the universal input range of 85 to 265 VAC and has a no-load power consumption of less than 150 mW at 265 VAC. The chip's on/off control scheme provides constant efficiency even at light loads, enabling easy compliance with recent efficiency standards.
Chargers using the LinkSwitch-LP require just 13 external components—the lowest component count for chargers of this type, according to the company. The design is simplified by the LinkSwitch-LP's use of a clampless technique that eliminates RCD (resistor, capacitor, diode) clamp-and-reset circuitry. In addition, the charger's output voltage is controlled from the primary side, thus eliminating the need for an opto coupler and associated components. The chip also has a special frequency jitter and "Filterfuse" input stage for EMI filtering with only a single external capacitor. The design of the company's E-Shield transformer (external component) eliminates the need for a Y capacitor. The chip has a hysteretic thermal shutdown feature to remove the need for external thermal protection components. It's compliant with all current and proposed energy standards worldwide.
Complete documentation can be secured by clicking here. LinkSwitchLP is available in lead-free, plastic through-hole DIP8 and surface-mountable SMD8 packages. The LNK562PN, a 1.9-watt part in a DIP8 package, is priced at 45 cents each in 1k pieces. The LNK564PN, a 3-watt part, is priced at 49 cents each. Small quantities of each type are available from factory stock, with production quantities available 4 weeks ARO.
The new product family is supported by a reference design kit, the DAK-85, which includes a fully tested 6-volt, 330-mA charger, an engineering test report, and product samples.
Power Integrations, 1-408-414-9200, www.powerint.com