Vishay Announces New P-Channel Load Switches With Integrated Slew-Rate Control

Vishay Intertechnology, Inc. released two new families of p-channel load switches optimized for high-side operation in 1.5 to 5V load-switching applications. The SiP4280A and SiP4282 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 such as cell phones, digital still cameras, hot-swap power supplies, notebook computers, and PDAs.

For maximum space savings, the SiP4282 offers typical on-resistance of 140mΩ at 5V and 175mΩ at 3V in the tiny SC-75 package. For applications requiring lower on-resistance but allowing more board space, the SiP4280A offers typical on-resistance of 80mΩ at 5V and 100mΩ at 3V in the 6-pin SOT-23 package. Both new load switches offer robust power-handling capacity while ensuring efficient use of battery power. Integrated slew-rate control allows the devices' output voltage to be ramped up more or less gradually, so designers of handheld products can conserve space by using smaller power-supply capacitors to handle the sags and surges currently encountered in the load-switching application.

The load switches are available in distinct versions featuring flexible turn-on and turn-off characteristics. The SiP4282-1 and SiP4280A-1 offer a slew-rate-limited turn-on time (typical) of 1ms, which reduces in-rush current when the device is turned on and thereby allows for the use of a small input capacitor – or no capacitor at all. The SiP4282-3 and SiP4280A-3 feature a slew-rate-limited turn-on time (typical) of 100µs, along with a shutdown load discharge circuit that enables rapid turn-off of a load circuit when the switch is disabled.

SiP4280A devices operate with input voltages from 1.5 to 5.5V, while the SiP4282 devices operate down to 1.8V. Typical quiescent current is 2.5mA for the SiP4282 and 0.025mA for the SiP4280A. These extremely low current levels allow for longer on-times in battery-powered equipment. The SiP4282 also provides an under-voltage lock-out (UVLO) feature that turns the switch off when an input under-voltage condition exists. Because the UVLO value is a low 1.4V, the end system can be operated using lower-voltage batteries. The ON/OFF control pin for each device is TTL-compatible and will also function with 2.5 to 5V CMOS logic systems. The devices' ESD rating is 4kV.

Samples and production quantities of the SiP4282 and SiP4280A load switches are available now, with lead times of eight weeks for larger orders. Pricing for U.S. delivery in 10,000 piece quantities is $1.95.