Dual 50kΩ digital potentiometer with I²C control
The Maxim Integrated DS1803E-050+ is a dual-channel, 256-tap digital potentiometer with a linear taper, 50kΩ end-to-end resistance, and I²C interface. Each of the two independent potentiometer circuits provides 256 wiper positions, giving fine granularity for volume control, gain trimming, or offset adjustment in mixed-signal designs. The part operates from a 2.7V to 5.5V supply, suiting both 3.3V and 5V logic rails. Housed in a 14-TSSOP surface-mount package, it includes a selectable address feature that allows up to two devices on the same I²C bus without address conflicts.
The 256 taps per channel give a step size of roughly 195Ω per tap (50kΩ / 256), which is fine enough for most audio level-setting and calibration loops. The linear taper means wiper resistance changes linearly with digital code—straightforward for firmware mapping, but not the right choice if you need a logarithmic (audio) taper for volume control. The 750ppm/°C temperature coefficient means the absolute resistance can drift about 3.75% over a 50°C swing; if your application needs stable gain over temperature, plan for that drift or consider a lower-tempco part. The wiper resistance of 400Ω typical adds a small series offset—negligible for high-impedance loads but worth factoring into divider ratios. The ±20% tolerance on the end-to-end resistance is typical for digital pots; it does not affect the ratiometric accuracy of the divider, only the absolute resistance.
It is ROHS3 compliant.