The AD5241/AD5242 provide a single-/dual-channel， 256- position， digitally controlled variable resistor （VR） device. These devices perform the same electronic adjustment function as a potentiometer， trimmer， or variable resistor. Each VR offers a completely programmable value of resistance between the A terminal and the wiper， or the B terminal and the wiper. For the AD5242， the fixed A-to-B terminal resistance of 10 k?， 100 k?， or 1 M? has a 1% channel-to-channel matching tolerance. The nominal temperature coefficient of both parts is 30 ppm/°C. Wiper position programming defaults to midscale at system power on. When powered， the VR wiper position is programmed by an I2 C-compatible， 2-wire serial data interface. Both parts have two extra programmable logic outputs available that enable users to drive digital loads， logic gates， LED drivers， and analog switches in their system. The AD5241/AD5242 are available in surface-mount， 14-lead SOIC and 16-lead SOIC packages and， for ultracompact solutions， 14-lead TSSOP and 16-lead TSSOP packages. All parts are guaranteed to operate over the extended temperature range of ?40°C to +105°C.