“Set It And Forget It ” With Programmable Digital Trimmer

The AD5273 64-step digital trimmer offers a one-time-programmable (OTP) digitally controlled variable resistor (VR) that performs the same electronic adjustment function as a variable resistor or potentiometer. The device replaces mechanical trimmers in "set and forget" factory adjustments. Variable resistance is provided under two-wire I²C-compatible program control. The OTP feature permanently sets the wiper position, which is functionally similar to placing epoxy on a mechanical trimmer. Factory programming software replaces external I²C controllers for faster board assembly. This device eliminates the need for careful matching of specific resistance values in electronic adjustment applications with poor tolerance distributions. The unit suits battery-powered electronic adjustment applications operating from 2.7- to 5.5-V supplies. The AD5273, which comes in an eight-lead SOT-23 package measuring 2.9 by 3 mm, costs $0.68 each in 1000-piece quantities.