256-Position, Digitally-Controlled Pot Packs Multiple Independently Programmable Channels

Performing the same adjustment function as a potentiometer, the AD5204 and AD5206 digitally-controlled, 8-bit, 256-position variable resistor (VR) devices are offered in resistance values of 10 k_, 50 k_ and 100 k_, suiting the VRs for use in precision industrial and instrumentation applications, such as power supply adjustment, gain and offset adjustment, and programmable voltage-to-current conversion. Each of the AD5204’s four channels and the AD5206’s six channels contains a fixed resistor with a wiper contact that taps the required resistor value at a point determined by digital code—the code is loaded into the devices’s 3-wire, SPI-compatible serial input register. Each VR has its own latch for holding its programmed resistance value. The digital pots can operate from a single 3V to 5V or dual ±2.7V supply, come housed in 24-lead SOIC, TSSOP and DIP packages, can operate over a -40°C to 85°C temperature range, and cost $2.47 each/1,000. ANALOG DEVICES INC., Wilmington, MA. (800) 262-5643.