Lexington, Mass. - STMicroelectronics' newest primary-side switch for off-line, low power AC/DC converters, the VIPer53E, touts an extended VDD range of 9-18 volts versus 9-14.5 volts for its VIPer53 (increased range implemented by eliminating an internal error amp) for improved flexibility in transformer design. The VIPer53E serves as an alternative to the VIPer53 when a power supply requires only secondary regulation. As with the VIPer53, the heatsink-free, DIP-8 device can handle 30 watts for a wide-range (85-265 VAC) mains input, or 50 watts for a single range (195-265 VAC) input, suitable for supplies powering DVD players, LCD monitors, set-top boxes, games consoles, and standby power supplies for servers.
The chip combines an enhanced current-mode PWM controller with a high-voltage MDmesh power MOSFET, a high-voltage start-up current source, overload, thermal, and short-circuit protection, and delayed device-reset circuitry. The chip's switching frequency can be externally set at up to 300 kHz. Advanced pulse-skipping circuitry minimizes the power drain in the chip's standby mode (down to 0.5 watt), enabling designers to easily meet the Blue Angel and Energy Star energy efficiency standards. The VIPer53E, also available in a PowerSO-10 package, is priced at 90 cents each in 10k quantities.