Low on-resistance, fast switching for precision analog paths
The MAX4645EUT+T from Maxim Integrated is a single-pole single-throw normally-open (SPST-NO) analog switch in a SOT-23-6 package. It is designed for routing analog or digital signals with minimal distortion, featuring a maximum on-resistance of 2.5 Ohm and switching times of 15 ns (tON) and 10 ns (tOFF). The 1.8 V to 5 V single-supply range makes it suitable for battery-powered portable equipment, data-acquisition front ends, and audio signal routing where low insertion loss and fast settling are required.
Charge injection and leakage — what they mean for the signal path
Charge injection is rated at 5 pC, which is the amount of charge transferred to the load when the switch turns off. In a sample-and-hold or integrator circuit, this glitch energy can cause a voltage step on the hold capacitor — 5 pC is low enough that with a 10 nF hold cap the step is under 0.5 mV, keeping errors in the microvolt range. Off-leakage current is a maximum of 250 pA at 25°C, so the switch does not appreciably discharge a high-impedance node during the off state.
Supply voltage and temperature — design margin considerations
The supply range from 1.8 V to 5 V covers the common 1.8 V, 2.5 V, 3.3 V, and 5 V logic rails. On-resistance is specified at the maximum value across the full -40°C to +85°C industrial temperature range, so the 2.5 Ohm ceiling holds even at the hot end where RON typically increases. The SOT-23-6 footprint is compact enough for dense PCB layouts in portable instrumentation or sensor interface modules.
Lifecycle and sourcing — active production, no LTB concern
The MAX4645EUT+T carries an active lifecycle status with ROHS3 compliance.