SPDT switch in SOT-23-6 — 60 Ohm on-resistance, 100 ns switching
The MAX4544EUT+T is a single-pole double-throw (SPDT) analog switch from Analog Devices, packaged in a 6-pin SOT-23. It routes one common terminal to either of two independent I/O ports, controlled by a single logic input. With a maximum on-resistance of 60 Ohm and channel-to-channel matching of 800 mOhm, this switch maintains consistent signal attenuation across both paths — important for precision analog multiplexing where gain matching matters. Switching times are 100 ns (ton) and 75 ns (toff) maximum, making it suitable for audio routing, data acquisition front-ends, and low-frequency signal multiplexing where the switching speed exceeds the signal bandwidth.
Signal integrity — charge injection and crosstalk
Charge injection is specified at 1 pC typical, which translates to a voltage glitch of roughly 125 µV into a 125 pF load — low enough to avoid audible pops in audio paths or settling errors in sample-and-hold circuits. Crosstalk between channels is -90 dB at 1 MHz, indicating strong isolation between the two signal paths. This is adequate for audio-frequency multiplexing and low-speed data acquisition where channel bleed-through must stay below the noise floor. Off-leakage current is a maximum of 100 pA, and channel capacitance (both source and drain off) is 8 pF each — these keep the signal path high-impedance when the switch is open, preserving the integrity of upstream sensor or amplifier outputs.
It is ROHS3 compliant, meeting the latest EU restriction-of-hazardous-substances directive for lead-free soldering processes.