AD5273,pdf datasheet (64-Posit

The AD5273 is a 64-position, one-time programmable (OTP) digital potentiometer4 that employs fuse link technology to achieve permanent program setting. This device performs the same electronic adjustment function as most mechanical trimmers and variable resistors. It allows unlimited adjustments before permanently setting the resistance values. The AD5273 is programmed using a 2-wire, I2C?-compatible digital control. During write mode, a fuse blow command is executed after the final value is determined, thereby freezing the wiper position at a given setting (analogous to placing epoxy on a mechanical trimmer). When the permanent setting is achieved, the value does not change, regardless of the supply variations or environ-mental stresses under normal operating conditions. To verify the success of permanent programming, Analog Devices, Inc., patterned the OTP validation such that the fuse status can be discerned from two validation bits in the read mode.