Slew-rate-controlled load switches offer range of fast turn-on times

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MALVERN, PA — Vishay Intertechnology, Inc. has released the SiP4280 family of p-channel load switches with slew-rate control for high-volume mobile phone and PDA power management applications that offer turn-on times between 0.5 and 1000 microseconds.

The SiP4280 switches turn on and turn off the power for the display, speakerphone, memory cards, and other such functions in portable electronic systems. Their integrated slew-rate control, which allows designers to control the time required to ramp up the voltage, means that designers can use smaller power-supply capacitors to handle the current sags and surges encountered in the load-switching applications. The result is a smaller circuit for handheld products.

The SiP4280 family of switches also conserve on space with their typical low on-resistance of 80 milliohms, ensuring efficient use of battery power. The SiP4280 devices are designed to handle 1 A of current and have an absolute maximum current rating of 2 A.

The switches give designers of portable electronics a choice of three specific controlled-slew rate options. For applications requiring a relatively slow slew rate, the SiP4280-1 version provides a typical 1000-microsecond turn-on time. For applications where a minimal level of slew-rate control is needed, the SiP4280-3 version provides a 100-microsecond turn-on time. The SiP4280-2 version provides no slew rate control and delivers turn-on times of typically less than 0.5 microseconds. Devices in the SiP4280 family are specified for a 1.8-V to 5.5-V input range, a 2.5-A typical quiescent current, and packaging in the 6-pin SOT-23 or 8-pin SC-70. An undervoltage lockout feature turns the switch off if the input voltage drops below 1.8 V. The SiP4280 can be used as a direct replacement for the AAT4280.

The switches cost $0.28 in 1,000-piece quantities. Click here for the data sheet.

Vishay Intertechnology, Incorporated, +1 619 336-0860,

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