The MAX4554/MAX4555/MAX4556 are CMOS analog ICs configured as force-sense switches for Kelvin sensing in automated test equipment (ATE). Each part contains high-current, low-resistance switches for forcing current, and higher resistance switches for sensing a voltage or switching guard signals. The MAX4554 contains two force switches, two sense switches, and two guard switches configured as two triple-pole/single-throw (3PST) normally open (NO) switches. The MAX4555 contains four independent single-pole/single-throw (SPST) normally closed (NC) switches, two force switches, and two sense switches. The MAX4556 contains three independent single-pole/double-throw (SPDT) switches, of which one is a force switch and two are sense switches.These devices operate from a single supply of +9V to +40V or dual supplies of ±4.5V to ±20V. On-resistance (6Ω max) is matched between switches to 1Ω max. Each switch can handle rail-to-rail analog signals. The off-leakage current is only 0.25nA at +25°C and 2.5nA at +85°C. The MAX4554 is also fully specified for +20V and -10V operation.All digital inputs have +0.8V and +2.4V logic thresholds, ensuring both TTL- and CMOS-logic compatibility.ApplicationsADSL with LoopbackAutomated Test Equipment (ATE)Automatic Calibration CircuitsCalibratorsPrecision Power Supplies