Low Power, Low Cost 2.5 V Reference AD680 FEATURES CONNECTION DIAGRAMS Low quiescent current at 250 A max Laser trimmed to high accuracy TP* 1 8 TP* 2.5 V 5 mV max (AN, AR grades) +V 2 7 TP* IN AD680 TEMP 3 6 V TOP VIEW OUT Trimmed temperature coefficient (Not to Scale) GND 4 5 NC 20 ppm/C max (AN, AR grades) Low noise at 8 V p-p from 0.1 Hz to 10 Hz NC = NO CONNECT *TP DENOTES FACTORY TEST POINT. 250 nV/Hz wideband NO CONNECTIONS SHOULD BE MADE TO THESE PINS. Temperature output pin (N, R packages) Available in three package styles Figure 1. 8-Lead PDIP and 8-Lead SOIC Pin Configuration 8-lead PDIP, 8-lead SOIC, and 3-pin TO-92 AD680 GENERAL DESCRIPTION BOTTOM VIEW (Not to Scale) The AD680 is a band gap voltage reference that provides a fixed 32 1 2.5 V output from inputs between 4.5 V and 36 V. The +V V GND IN OUT architecture of the AD680 enables the reference to be operated at a very low quiescent current while still realizing excellent dc Figure 2. Connection Diagram TO-92 characteristics and noise performance. Trimming of the high stability thin-film resistors is performed for initial accuracy and PRODUCT HIGHLIGHTS temperature coefficient, resulting in low errors over temperature. 1. High Accuracy. The precision dc characteristics of the AD680 make it ideal for The AD680 band gap reference operates on a very low use as a reference for DACs that require an external precision quiescent current which rivals that of many 2-terminal reference. The device is also ideal for ADCs and, in general, can references. This makes the complete, higher accuracy AD680 ideal for use in power-sensitive applications. offer better performance than the standard on-chip references. Based upon its low quiescent current, which rivals that of many 2. Low Errors. incomplete 2-terminal references, the AD680 is recommended Laser trimming of both initial accuracy and temperature coef- for low power applications, such as hand-held, battery-operated ficients results in low errors over temperature without the use equipment. of external components. The AD680AN and AD680AR have A temperature output pin is provided on the 8-lead package a maximum variation of 6.25 mV between 40C and +85C. versions of the AD680. The temperature output pin provides an 3. Low Noise. output voltage that varies linearly with temperature and allows The AD680 noise is low, typically 8 V p-p from 0.1 Hz to the AD680 to be configured as a temperature transducer while 10 Hz. Spectral density is also low, typically 250 nV/Hz. providing a stable 2.5 V output. 4. Temperature Transducer. The AD680 is available in five grades. The AD680AN is speci- The temperature output pin on the 8-lead package versions fied for operation from 40C to +85C, while the AD680JN is enables the AD680 to be configured as a temperature specified for 0C to 70C operation. Both the AD680AN and transducer. AD680JN are available in 8-lead PDIP packages. The AD680AR is specified for operation from 40C to +85C, while the 5. Low Cost. AD680JR is specified for 0C to 70C operation. Both are PDIP packaging provides machine insertability, while SOIC available in 8-lead SOIC packages. The AD680JT is specified for packaging provides surface-mount capability. TO-92 0C to 70C operation and is available in a 3-pin TO-92 packaging offers a cost-effective alternative to 2-terminal package. references, offering a complete solution in the same package in which 2-terminal references are usually found. Rev. H 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. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 2005 Analog Devices, Inc. All rights reserved. 00813-004 00813-003AD680 TABLE OF CONTENTS Specifications..................................................................................... 3 Load Regulation ............................................................................8 Absolute Maximum Ratings............................................................ 4 Temperature Performance............................................................8 Output Protection ........................................................................ 4 Temperature Output Pin ..............................................................9 ESD Caution.................................................................................. 4 Differential Temperature Transducer .........................................9 Pin Configuration and Connection Diagram............................... 5 Low Power, Low Voltage Reference for Data Converters ........9 Theory of Operation ........................................................................ 6 4.5 V Reference from a 5 V Supply .......................................... 10 Applying the AD680 .................................................................... 6 Voltage Regulator for Portable Equipment............................. 10 Noise Performance ....................................................................... 6 Outline Dimensions ....................................................................... 11 Turn-on Time................................................................................ 7 Ordering Guide .......................................................................... 12 Dynamic Performance................................................................. 7 REVISION HISTORY 8/05Rev. G to Rev. H Changes to Ordering Guide ..........................................................11 12/04Rev. F to Rev. G Updated Format ................................................................. Universal Changes to Ordering Guide ..........................................................11 5/04Rev. E to Rev. F Changes to ORDERING GUIDE ...................................................3 5/03Rev. D to Rev. E Changes to ORDERING GUIDE ...................................................3 Added ESD Caution ..........................................................................3 Changes to Figure 20.........................................................................7 Updated OUTLINE DIMENSIONS ...............................................8 7/01Rev. C to Rev. D Changes to SPECIFICATIONS........................................................2 Changes to ORDERING GUIDE ....................................................3 Table I added ......................................................................................6 Rev. H Page 2 of 12