Quad SPST-NC switch with 175 Ohm Ron and -90dB isolation
The DG211DY+ is a quad SPST normally-closed analog switch from Analog Devices, built on a CMOS process that delivers 175 Ohm max on-resistance with 5pF channel capacitance on both source and drain sides. Each of the four switches is a 1:1 multiplexer/demultiplexer — the NC configuration means the channel is closed when the control pin is low, useful for fail-safe signal routing where the path should stay connected on power loss.
Switching speed and crosstalk floor
Maximum turn-on time is 1µs, turn-off 500ns — the asymmetry means the switch closes slower than it opens, a detail that matters when sequencing analog paths to avoid momentary shorts between rails. Crosstalk is rated at -90dB at 100kHz, which is the isolation between channels at that frequency — for a 16-bit ADC front-end, this keeps the feedthrough from an adjacent channel below 1 LSB at full scale. Off-state leakage is 5nA max per switch, and the 5pF drain/source capacitance sets the bandwidth ceiling — into a 10kOhm load the -3dB point is around 3.2 MHz, so this part suits audio, instrumentation, and low-frequency multiplexing.
The dual-supply range is ±4.5V to ±18V, covering standard ±5V, ±12V, and ±15V rails — the on-resistance varies with supply voltage, so the 175 Ohm max figure is at the minimum supply; at ±15V Ron is typically lower.
Package and board-fit
Supplied in tube packaging; the part is also available in tape-and-reel under a different order code for automated assembly.
RoHS3 compliant, with no exemptions — the + suffix on the order code indicates lead-free and RoHS-compliant finish.