High Precision Voltage Reference AD588* FUNCTIONAL BLOCK DIAGRAM
FEATURES Low Drift: 1.5 ppm/؇C Low Initial Error: 1 mV Pin-Programmable Output +10 V, +5 V, ؎5 V Tracking, –5 V, –10 V Flexible Output Force and Sense Terminals High Impedance Ground Sense Machine-lnsertable DIP Packaging MIL-STD-883 Compliant Versions Available
A3 OUT SENSE
A3 OUT FORCE
A4 OUT SENSE
A4 OUT FORCE
RB A1 R4
The AD588 represents a major advance in the state-of-the-art in monolithic voltage references. Low initial error and low temperature drift give the AD588 absolute accuracy performance previously not available in monolithic form. The AD588 uses a proprietary ion-implanted buried Zener diode, and laser-waferdrift trimming of high stability thin-film resistors to provide outstanding performance at low cost. The AD588 includes the basic reference cell and three additional amplifiers which provide pin-programmable output ranges. The amplifiers are laser-trimmed for low offset and low drift to maintain the accuracy of the reference. The amplifiers are configured to allow Kelvin connections to the load and/or boosters for driving long lines or high-current loads, delivering the full accuracy of the AD588 where it is required in the application circuit. The low initial error allows the AD588 to be used as a system reference in precision measurement applications requiring 12-bit absolute accuracy. In such systems, the AD588 can provide a known voltage for system calibration in software and the low drift allows compensation for the drift of other components in a system. Manual system calibration and the cost of periodic recalibration can therefore be eliminated. Furthermore, the mechanical instability of a trimming potentiometer and the potential for improper calibration can be eliminated by using the AD588 in conjunction autocalibration software. The AD588 is available in seven versions. The AD588 JQ and KQ grades are packaged in a 16-pin cerdip and are specified for 0°C to +70°C operation. AD588AQ and BQ grades are packaged in a 16-pin cerdip and are specified for the –25°C to +85°C industrial temperature range. The ceramic AD588SQ and TQ grades are specified for the full military/aerospace temperature range. For military surface mount applications, the AD588SE and TE grades are also available in 20-pin LCC packages.
GND SENSE +IN
GND SENSE –IN
13 A4 IN
1. The AD588 offers 12-bit absolute accuracy without any user adjustments. Optional fine-trim connections are provided for applications requiring higher precision. The fine-trimming does not alter the operating conditions of the Zener or the buffer amplifiers and thus does not increase the temperature drift. 2. Output noise of the AD588 is very low—typically 6 µV p. A pin is provided for additional noise filtering using an external capacitor. 3. A precision ± 5 V tracking mode with Kelvin output connections is available with no external components. Tracking error is less than one millivolt and a fine-trim is available for applications requiring exact symmetry between the +5 V and –5 V outputs. 4. Pin strapping capability allows configuration of a wide variety of outputs: ± 5 V, +5 V and +10 V, –5 V & –10 V dual outputs or +5 V, –5 V, +10 V, –10 V single outputs. 5. Extensive temperature testing at –55°C, –25°C, 0°C, +25°C, +50°C, +70°C, +85°C and +125°C ensures that the specified temperature coefficient is truly representative of device performance.
- Covered by Patent Number 4,644,253.
REV. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 Fax: 617/326-8703