Single SPDT analog switch saves space in portable consumer and medical devices

Vishay Intertechnology is offering a new single SPDT analog switch that is their first device in the new ultra-compact µDFN6 package. Ideal for analog and digital signal switching in portable consumer and medical devices, the Vishay Siliconix DG3257 achieves low resistance of 5Ohm at 4.2V while delivering improved high bandwidth, reduced parasitic capacitance, and a power-down protection feature. Measuring just 1mm x 1mm x 0.35mm, the device released today is 29% smaller and 36% thinner than switches in the mQFN6 package. This allows the device 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 new device achieves extremely high bandwidth of over 700MHz. It features break-before-make switching with a 17ns turn-on time and an ultra-low 100ps propagation delay. The switch features -32dB crosstalk at 240MHz — a claimed 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 9pF and CS(OFF) of 3pF. The device 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 device 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 1.5 µA, which is 90% lower than competing devices.