Quad SPST-NC switch in a 16-SOIC package
The Maxim Integrated DG444DY+ is a quad single-pole single-throw normally-closed (SPST-NC) analog switch in a 16-SOIC surface-mount package. It handles four independent 1:1 multiplexer/demultiplexer channels, each with a maximum on-resistance of 85 Ohm.
Supply flexibility and signal range
That dual-supply capability means it can switch bipolar signals without level-shifting — handy when you are routing audio or bipolar sensor outputs through the same BOM line. The -100 dB crosstalk at 1 MHz keeps adjacent channels from bleeding into each other, which matters when you are multiplexing low-level analog signals in a data-acquisition front end. Charge injection is 5 pC typical — low enough that sample-and-hold circuits and precision DAC outputs see minimal glitch energy when the switch toggles.
Switching speed and on-resistance matching
Turn-on time is 250 ns max, turn-off 140 ns max. That 250 ns ceiling sets the channel-switching rate in a multiplexed ADC system — the switch settles before the converter starts its acquisition window. Channel-to-channel on-resistance matching is 4 Ohm max, so the gain error across channels in a programmable-gain amplifier stays tight. The 4 pF off-capacitance on both source and drain keeps the signal path from loading the source when the channel is open.
Temperature range and leakage
Off-leakage is 500 pA max, so high-impedance sensor inputs do not see a significant offset from the switch itself.