Datasheet AD688 (Analog Devices)

High Precision ±10 V Reference AD688 FEATURES FUNCTIONAL BLOCK DIAGRAM ±10 V tracking outputs NOISE +10V OUT REDUCTION VHIGH A3 IN SENSE Kelvin connections 7 6 4 3 Low tracking error: 1.5 mV Low initial error: 2.0 mV +10V OUT A3 1 FORCE Low drift: 1.5 ppm/°C RB Low noise: 6 μV p-p A1 AD688 –10V OUT 14 Flexible output force and sense terminals R1 R4 SENSE High impedance ground sense –10V OUT A4 15 Wide body SOIC and CERDIP packages R2 FORCE R5 R6 2 +VS GENERAL DESCRIPTION R3 A2 16 –VS
The AD688 is a high precision ±10 V tracking reference. Low tracking error, low initial error, and low temperature drift give
5 9 10 8 12 11 13 GAIN GND NC V NC A4 IN
the AD688 reference absolute ±10 V accuracy performance
LOW BAL ADJ SENSE ADJ
001
+IN
previously unavailable in monolithic form. The AD688 uses a
NC = NO CONNECT
00815- proprietary ion-implanted buried Zener diode, and laser wafer Figure 1. drift trimming of high stability thin-film resistors to provide outstanding performance. The AD688 includes the basic reference cell and three additional amplifiers. The amplifiers are laser-trimmed for low offset and low drift and maintain the accuracy of the reference.
PRODUCT HIGHLIGHTS
The amplifiers are configured to allow Kelvin connections to the load and/or boosters for driving long lines or high current 1. Precision Tracking. The AD688 offers precision tracking loads, delivering the full accuracy of the AD688 where it is ±10 V Kelvin output connections with no external required in the application circuit. components. Tracking error is less than 1.5 mV and fine- trim is available for applications requiring exact symmetry The low initial error allows the AD688 to be used as a system between the +10 V and −10 V outputs. reference in precision measurement applications requiring 12-bit absolute accuracy. In such systems, the AD688 can 2. Accuracy. The AD688 offers 12-bit absolute accuracy provide a known voltage for system calibration; the cost of without any user adjustments. Optional fine-trim periodic recalibration can therefore be eliminated. connections are provided for applications requiring higher Furthermore, the mechanical instability of a trimming precision. The fine-trimming does not alter the operating potentiometer and the potential for improper calibration can be conditions of the Zener or the buffer amplifiers and thus eliminated by using the AD688 and calibration software. does not increase the temperature drift. The AD688 is available in commercial version. Specified over 3. Low output noise. Output noise of the AD688 is low— the −40oC to +85oC temperature range, the AD688 is offered in typically 6 μV p-p. A pin is provided for broadband noise wide body 16-lead SOIC and 16-lead CERDIP packages, filtering using an external capacitor.
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 that may result from its use. Specifications subject to change without notice. No license is granted by implication One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. or otherwise under any patent or patent rights of Analog Devices. Trademarks and Tel: 781.329.4700 www.analog.com registered trademarks are the property of their respective owners. Fax: 781.461.3113 © 2005 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS THEORY OF OPERATION APPLICATIONS CALIBRATION NOISE PERFORMANCE AND REDUCTION TURN ON TIME TEMPERATURE PERFORMANCE KELVIN CONNECTIONS DYNAMIC PERFORMANCE BRIDGE DRIVER CIRCUIT OUTLINE DIMENSIONS ORDERING GUIDE