Switch topology and on-resistance floor
The MAX4685EUB+T is a dual single-pole double-throw (SPDT) switch, configured as a 2:1 multiplexer/demultiplexer per channel. With a maximum on-resistance of 800mOhm and channel-to-channel matching of 60mOhm, the switch introduces minimal series resistance in the signal path — important for precision analog routing where voltage drop across the switch would otherwise shift the signal level.
Switching speed and signal integrity
Turn-on time is 50ns max, turn-off 30ns max — the asymmetric timing means the switch breaks before it makes, preventing momentary cross-conduction between the two output paths during channel change. Crosstalk is rated at -68dB at 100kHz, providing adequate isolation for audio line-level signals or low-frequency analog multiplexing where bleed between channels would degrade the signal-to-noise ratio. Charge injection is 200pC typical — this is the amount of charge dumped onto the signal node when the switch toggles. In a high-impedance sample-and-hold or ADC front-end, that 200pC spike can shift the held voltage by several millivolts if the source impedance is above 10kOhm. The 1nA max off-leakage keeps the DC error negligible once the switch settles.
Package and board-fit
Housed in a 10-TFSOP/MSOP (3.00mm width) package, also designated as 10-uMAX/uSOP. The 0.118-inch body width fits standard narrow-SOIC footprints with minor pad adjustments. Supplied in Tape & Reel (TR) or Cut Tape (CT) — the reel option suits automated pick-and-place for volume builds.