P-channel Load Switches
A new family of p-channel load switches with slew-rate control for high-volume mobile phone and PDA power management applications is available from Vishay Intertechnology, Inc. The 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. 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 < 0.5 microseconds. Devices in the SiP4280 family are specified for a 1.8 to 5.5 V input range, and a 2.5µA typical quiescent current.
Vishay Intertechnology, Inc.