Dual 50 kΩ rheostat with non-volatile wiper storage
The DS1859E-050+ from Maxim Integrated is a dual-channel digital rheostat with a 50 kΩ end-to-end resistance and 256 tap positions per channel. Each channel operates as a two-terminal variable resistor — the wiper position is stored in non-volatile memory, so the setting holds through a power cycle without host intervention. The part communicates over an I²C bus and includes a local temperature sensor, letting a controller read die temperature and adjust the wiper for compensation. The linear taper suits voltage-divider and current-bias trimming in bias supplies, sensor offset adjust, and laser-driver calibration circuits. Supply range is 2.85 V to 5.5 V, and the operating temperature covers -40°C to +95°C for industrial and telecom environments.
Integrated temperature sensor — a differentiator for thermal-drift compensation
The on-chip temperature sensor is readable over the same I²C bus. In an optical-module bias circuit or a precision voltage reference, the host can read the die temperature and adjust the wiper to counteract the 50 ppm/°C temperature coefficient of the resistance element. This closed-loop compensation keeps the set point stable across the -40°C to +95°C range without an external thermistor or ADC channel.