The AD688 is a high-accuracy ± 10 V tracking reference source. The device features low tracking error, low initial error, and low temperature drift, resulting in unprecedented absolute ± 10 V accuracy performance per chip. It features a proprietary ion implantation embedded Zener diode and laser wafer drift adjustment for highly stable thin-film resistors, allowing it to provide excellent performance at a lower cost.
The AD688 has a built-in base reference and three additional amplifiers. These amplifiers are laser-tuned for low offset and low drift characteristics, maintaining the accuracy of the reference voltage source. The amplifier configuration allows Kelvin connections to the load and/or booster to drive long lines or high-current loads, providing all the AD688 accuracy required for the application circuit.
The AD688's low initial error makes it suitable for use as a system reference for precision measurement applications requiring 12-bit absolute accuracy. In such a system, the AD688 can provide a known voltage for system calibration, thus eliminating the cost of regular recalibration. In addition, using the AD688 with calibration software eliminates mechanical instability and improper calibration of the adjustment potentiometer.
The AD688 is available in three models. The AD688 AQ and BQ stages are available in a 16-pin CERDIP (0.3") package and are rated for an operating temperature range of -40°C to +85°C. Class AD688SQ is rated for operating temperatures ranging from -55°C to +125°C.