SPST switch provides output protection and detection solution

29-09-2020 | Analog Devices | Connectors, Switches & EMECH

The Analog Devices ADG5401F main channel switch is an SPST, low on-resistance switch that provides overvoltage protection, power off protection, and overvoltage detection on the source pins (S and SFB). The device also offers a protected secondary feedback channel for usage with DAC or amplifier outputs.

When no power supplies are present, the switch stays in the off condition, and the switch inputs are high impedance. When powered, if the analog input signal levels on the S pin surpass VDD or VSS by a threshold voltage the switch turns off, the open-drain FF pin pulls to a logic low, and a path between the D and DFB pins is switched on to stop an open-loop condition on the amplifier output. Input signal levels up to +60V or -60V relative to ground are blocked, in both the powered and unpowered condition. The selectable POC pin function enables the protected switch terminal, S, to be attached to GND to minimise glitches on the output. The switch turns on with a Logic 1 input and conducts just as well in both directions. The digital input is compatible with 1.8V logic inputs across the whole operating supply range.

Typical applications include DAC output protection, amplifier output protection, analog output modules, process control/distributed control systems, data acquisition, and instrumentation.

By Natasha Shek