The AD5227 is Analog Devices’ latest 64-step up/down control digital potentiometer1 。 This device performs the same electronic adjustment function as a 5 V potentiometer or variable resistor. Its simple 3-wire up/down interface allows manual switching or high speed digital control. The AD5227 presets to midscale at power-up. When CS is enabled， the devices changes step at every clock pulse. The direction is determined by the state of the U/D pin （see ）。 The interface is simple to activate by any host controller， discrete logic， or manually with a rotary encoder or pushbuttons. The AD5227’s 64-step resolution， small footprint， and simple interface enable it to replace mechanical potentiometers and trimmers with typically 6× improved resolution， solid-state reliability， and design layout flexibility， resulting in a considerable cost savings in end users’ systems. Table 1 1 The terms digital potentiometer and RDAC are used interchangeably. The AD5227 is available in a compact thin SOT-23-8 （TSOT-8） Pb-free package. The part is guaranteed to operate over the automotive temperature range of ?40°C to +105°C. Users who consider EEMEM potentiometers should refer to some recommendations in the Applications section.