Dual 50k rheostat with an on-die temperature sensor
The Maxim Integrated DS1859B-050/TR is a dual-channel, non-volatile digital rheostat with a linear taper, 256 taps per channel, and a total end-to-end resistance of 50kΩ per channel. Each channel operates independently as a two-terminal variable resistor (rheostat configuration). The part integrates a temperature sensor on the same die, allowing the system to read die temperature over the serial interface and adjust the wiper setting accordingly — useful for closed-loop bias calibration or temperature-compensated trimming without an external thermistor. The 50 ppm/°C temperature coefficient keeps the set resistance stable across the rated temperature span — a practical concern when the rheostat sets a bias point or a reference current that must hold within a few percent over the equipment's operating season.
256 taps and non-volatile memory — what they mean for the BOM
The ±20% resistance tolerance is the absolute end-to-end tolerance of the full 50kΩ resistor string. In a rheostat configuration the wiper resistance ratio between two positions is much tighter than the absolute value, so the tolerance mainly affects the total range available, not the step-to-step linearity. If the design requires a precise absolute resistance, plan for a one-time calibration step that stores the correction in the non-volatile register.
Package and footprint
Housed in a 16-TSSOP package (4.40 mm body width, 0.173-inch pitch), the DS1859B-050/TR is a surface-mount part that fits on a standard PCB without requiring a fine-pitch assembly line. The supplier device package is 16-TSSOP. The Bulk shipping option means the parts arrive in tubes or trays, not tape-and-reel — verify feeder compatibility if your CM runs a high-speed pick-and-place line that expects tape.
Lifecycle and sourcing
For a BOM line that needs a dual digital rheostat with an integrated temperature sensor, this part is a safe selection for new designs and ongoing production.