Slew-Rate-Controlled 1-A Load Switches from Vishay Siliconix Offer Designers Turn-On Options
A new family of p-channel load switches with slew-rate control for high-volume mobile phone and PDA power management applications has been announced by Vishay Intertechnology Inc.
The new SiP4280 devices will be used to 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, allowing output voltage to be ramped up more or less gradually, means that designers can supply smaller power-supply capacitors to handle the current sags and surges encountered in the load-switching application, saving space in handheld products.
The new devices 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 device family announced today provides a choice of 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-µA 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 new device complements the wide range of Vishay Siliconix power-switching products, which include the current-limited SiP4610A/B (1 A), the Si4701BDY (7 A) load switch with level-shift, and the LITTLE FOOT® Plus families of power MOSFETs with integrated drivers and Schottky diodes.
Samples and production quantities of the new slew-rate-controlled load switches are available now, with lead times of six to eight weeks for larger orders. Pricing for U.S. delivery in 1,000-piece quantities starts at $0.28.
