The DS3904/DS3905 contain three nonvolatile (NV) low temperature coefficient, variable digital resistors. Each resistor has 128 user-selectable positions. Additionally, the DS3904/DS3905 have a high-impedance setting that allows each resistor to function as a digital switch. The DS3904/DS3905 can operate over a 2.7V to 5.5V supply voltage range, and communication with the device is achieved through a 2-wire serial interface. Address pins allow multiple DS3904/DS3905s to operate on the same two-wire bus. The DS3904 has one address pin, allowing two DS3904s to share the bus, while the DS3905 has three address pins, allowing up to eight DS3905s to share a common bus. The low-cost and small size of the DS3904/DS3905 make them ideal replacements for conventional mechanical trimming resistors.