Power devices scale the peaks

PeakSwitch is the name for a new family of ICs for power supplies with peak-to-continuous power ratios of up to 3:1.

Developed by Power Integrations, PeakSwitch is a new family of ICs for power supplies with peak-to-continuous power ratios of up to 3:1.

The industry's first monolithic power-conversion IC with peak-mode operation, PeakSwitch enables highly integrated, energy-efficient power supplies for applications such as printers, personal video recorders (PVRs), audio amplifiers, broadband modems and DC motor drives.

Printers - an ideal application for PeakSwitch - require steep, momentary spikes in power delivery when a print job is initiated.

For example, an inkjet printer that operates at a continuous level of 30W during printing might require a burst of up to 80W in order to activate the paper-advance motor.

PeakSwitch supplies this burst by automatically increasing the switching frequency of the IC's integrated MOSFET for several milliseconds before returning to continuous-mode operation.

This approach allows the use of transformers, capacitors and other components sized for the power supply's average continuous power rather than its peak power level.

PeakSwitch features a 700V MOSFET and low-voltage control circuitry integrated on a monolithic IC.

The device employs on/off control, providing low standby power consumption as well as constant active-mode efficiency.

This enables compliance with all current energy-efficiency standards, including the proposed Energy Star efficiency standard for printers, which specifies power budgets during standby, sleep and active operation.

Other key features include integrated auto-restart, hysteretic thermal shutdown and integrated frequency jittering to minimise EMI.

"Until now, power supplies had to be overengineered to accommodate high levels of peak power use", said Balu Balakrishnan, President and CEO of Power Integrations.

"With PeakSwitch, designs only need to accommodate a power supply's continuous power requirements".

"As a result, designers can use smaller transformers and other components, resulting in a lower-cost power supply".

PeakSwitch is available in lead-free, plastic through-hole DIP-8 and higher power standard TO-220 packages.

Pricing in 1000-piece quantities for the PKS604PN, a 16W continuous, 44W peak part in a DIP-8 package is $0.91.

The PKS606YN, a 45W continuous, 86W peak part in a TO-220 package is priced at $1.65 each.

Small quantities of most types are available from factory stock, with production quantities available six weeks ARO.

All part types are available today, with the exception of the PKS603PN, which will be available in Q2.

Complete documentation for the PeakSwitch family is on the Power Integrations website.

Design support includes a datasheet, an application note (AN 41), a reference design kit (DAK 93) containing an operational 32W continuous, 85W peak, universal input AC/DC power supply and product samples, and the company's power supply design software program, PI Expert.

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