Dual SP4T switch with 1-ohm on-resistance for precision analog multiplexing
The Maxim Integrated MAX4782ETE+T is a dual single-pole, four-throw (SP4T) analog multiplexer in a 16-TQFN (3x3 mm) package with an exposed pad for thermal management. Each of the two switch circuits routes one common pin to any of four independent channels, controlled by a 2-bit address bus. The headline spec is a maximum on-state resistance of 1 ohm, which keeps signal attenuation and distortion negligible in precision analog paths. Channel-to-channel matching is held to 300 milliohms, so the insertion loss stays consistent across all four positions.
Crosstalk and charge injection — what they mean for your signal chain
Crosstalk is rated at -80 dB at 1 MHz, which means a signal on one active channel couples into an off channel at a level 80 dB below the carrier. For a 16-bit ADC system with a 2-V reference, that puts the feedthrough below 200 µV — well into the noise floor for most industrial multiplexing applications. Charge injection is specified at -110 pC, a figure that matters when the switch drives a high-impedance sample-and-hold capacitor: the injected charge creates a voltage glitch equal to Q/C, so a 10-pF hold cap sees roughly an 11-mV step. That glitch settles within the 25-ns turn-on time, but the design should budget for it in the acquisition window.
Supply range, leakage, and capacitance — fit for battery-powered and precision circuits
The part operates from a single supply between 1.6 V and 3.6 V, covering the 1.8-V and 3.3-V logic rails common in portable and IoT designs. Off-channel leakage is a maximum of 2 nA, so it does not load the analog bus when the channel is deselected. Channel capacitance is 38 pF on the source side and 158 pF on the drain side — the higher drain capacitance is the sum of all four off-channel capacitances plus the common node. That 158-pF load on the common output matters for settling time when driving an ADC input; a 1-kΩ source resistance gives a 158-ns time constant, which is within the 25-ns switching window but worth accounting for in the acquisition budget.
Active lifecycle and ROHS3 compliance — no end-of-life risk for new designs
The MAX4782ETE+T carries an active lifecycle status from Maxim Integrated (now part of Analog Devices). The part is ROHS3 compliant, meeting the current European Union directive for lead-free and restricted-substance limits.