Description

The AD581 is a 3-pin, temperature compensated, monolithic, band gap voltage reference that provides a precise 10.00 V output from an unregulated input level ranging from 12 V to 30 V. Laser wafer trimming (LWT) is used to trim both the initial error at +25°C as well as the temperature coefficient, resulting in high precision performance previously available only in expensive hybrids or oven regulated modules. The 5 mV initial error tolerance and 5 ppm/°C guaranteed temperature coefficient of the AD581L is available in a monolithic voltage reference.The band gap circuit design used in the AD581 offers several advantages over classical Zener breakdown diode techniques. Most important, no external components are required to achieve full accuracy and significant stability to low power systems. In addition, total supply current to the device, including the output buffer amplifier (which can supply up to 10 mA) is typically 750 μA. The long-term stability of the band gap design is equivalent to selected Zener reference diodes.The AD581 is recommended for use as a reference for 8-, 10- or 12-bit digital-to-analog converters (DACs) that require an external precision reference. The device is also ideal for all types of analog-to-digital converters (ADCs) up to 14-bit accuracy, either successive approximation or integrating designs, and can generally offer better performance than that provided by standard self-contained references.The AD581J, K, and L are specified for operation from 0°C to +70°C; the AD581S, T, and U are specified for the -55°C to +125°C range. All grades are packaged in a hermetically sealed three-terminal TO-5 metal can.PRODUCT HIGHLIGHTS Laser trimming of both initial accuracy and temperature coefficient results in very low errors over temperature without the use of external components. The AD581L has a maximum deviation from 10.000 V of ±7.25 mV from 0°C to 70°C, whereas the AD581U guarantees ±15 mV maximum total error without external trims from −55°C to +125°C. Because the laser trimming is done on the wafer prior to separation into individual chips, the AD581 is extremely valuable to hybrid designers for its ease of use, lack of required external trims, and inherent high performance. The AD581 can also be operated in a 2-pin Zener mode to provide a precision −10 V reference with just one external resistor to the unregulated supply. The performance in this mode is nearly equal to that of the standard 3-pin configuration. Advanced circuit design using the band gap concept allows the AD581 to give full performance with an unregulated input voltage down to 13 V. With an external resistor, the device operates with a supply as low as 11.4 V. 5. The AD581 is available in versions compliant with MILSTD-883. Refer to the military datasheet for detailed specifications.