New Industry Products

SPDT Analog Switch Saves Space in Portable Consumer and Medical Devices

October 16, 2017 by Paul Shepard

Vishay Intertechnology, Inc. today introduced a new single SPDT analog switch that is the company's first device in the new ultra-compact μDFN6 package. Designed for analog and digital signal switching in portable consumer and medical devices, the Vishay Siliconix DG3257 achieves low resistance of 5Ω at 4.2V while delivering improved high bandwidth, reduced parasitic capacitance, and a power-down protection feature.

Measuring just 1 mm by 1 mm by 0.35 mm, the device released today is 29 % smaller and 36 % thinner than switches in the mQFN6 package. This allows the DG3257 to save valuable PCB space in smartphones, tablets, and e-readers; wearable devices such as smart watches and fitness trackers; portable medical instrumentation; cameras and audio devices; IoT applications; computers and peripherals; and data storage devices.

While previous generation devices offer -3dB bandwidth of 300MHz, the DG3257 achieves extremely high bandwidth of over 700MHz. This 5Ω SPDT device features break-before-make switching with a 17ns turn-on time and a 100ps propagation delay.

The switch features ‑32dB crosstalk at 240MHz — a 10dB improvement over competing solutions — and -33dB off-isolation. The device is fabricated with a high density sub-micron CMOS process to deliver 50% lower parasitic capacitance CD(ON) of 9 pF and CS(OFF) of 3pF.

The DG3257 handles bidirectional signal flow with minimal distortion and can be powered directly from a one-cell Li-ion battery. Designed to operate from 1.65V to 5.5V, the DG3257 guarantees less than 1μA of leakage current in the power-down condition.

This feature prevents excessive current from feeding into the switch when the power supply is removed. The device has a 1.4V logic threshold to ensure low voltage TTL/CMOS compatibility. When interfacing with low voltage MCUs, the switch offers guaranteed maximum power consumption of 1.5μA, which is 90% lower than competing devices.

The RoHS-compliant device offers ESD tolerance >6kV (human body model) and latch up current of 300mA per JESD78.

Samples and production quantities of the new analog switch are available now, with lead times of 10 weeks for large orders. Pricing for U.S. delivery only starts at $0.20 per piece in 1,000-piece quantities.