AD5207,pdf datasheet (Digital

The AD5207 provides dual channel, 256-position, digitally
controlled variable resistor (VR) devices that perform the same
electronic adjustment function as a potentiometer or variable
resistor. Each channel of the AD5207 contains a fixed resistor with
a wiper contact that taps the fixed resistor value at a point
determined by a digital code loaded into the SPI-compatible
serial-input register. The resistance between the wiper and either
end point of the fixed resistor varies linearly with respect to the
digital code transferred into the VR latch. The variable resistor
offers a completely programmable value of resistance, between
the A Terminal and the wiper or the B Terminal and the wiper.
The fixed A-to-B terminal resistance of 10 kΩ, 50 kΩ or 100 kΩ
has a ±1% channel-to-channel matching tolerance with a nominal
temperature coefficient of 500 ppm/°C. A unique switching
circuit minimizes the high glitch inherent in traditional switched
resistor designs and avoids any make-before-break or breakbefore-
make operation.