Quad 100k rheostat with 129-tap resolution
The MCP4432-104E/ST is a quad-channel digital rheostat from Microchip's MCP44XX family, each channel offering 100 kΩ end-to-end resistance with 129 tap positions — enough resolution for fine-grained analog trimming in bias networks, sensor offset calibration, or programmable gain stages. The I²C interface with selectable address (the 'Selectable Address' feature) lets up to eight devices share the same bus, giving 32 independent rheostat channels on one two-wire bus.
The 150 ppm/°C temperature coefficient on resistance means a 100 kΩ nominal value drifts about 1.5 kΩ over a 100°C swing — acceptable for many trim applications, but worth derating if the divider ratio must stay tight across the full temperature range.
Housed in a 14-lead TSSOP (4.40 mm body width), the MCP4432-104E/ST fits a compact surface-mount footprint. Supplied in tube packaging — typical for prototype quantities or low-volume production. For reeled tape-and-reel packaging, check the alternate order code suffix at RFQ.
Volatile memory — wiper resets on power-up
The volatile memory type means the wiper position defaults to mid-scale (tap 64 of 129) at power-on and is lost when the supply drops. The firmware must re-initialise the wiper registers after every power cycle if a specific starting value is required. The 75 Ω typical wiper resistance adds a small series offset — negligible for a 100 kΩ divider but relevant if the rheostat drives a low-impedance node directly.
ROHS3 compliant, with no restricted substances above the threshold limits.