2.5 V/3.0 V High Precision Reference Data Sheet AD780 FEATURES FUNCTIONAL BLOCK DIAGRAM +V DNC IN Pin programmable 2.5 V or 3.0 V output 2 7 Ultralow drift: 3 ppm/C max AD780 High accuracy: 2.5 V or 3.0 V 1 mV max Low noise: 100 nV/Hz R10 R11 Noise reduction capability DNC 1 6 V OUT Low quiescent current: 1 mA max R13 Output trim capability Q6 Q7 R16 Plug-in upgrade for present references 5 TRIM R5 Temperature output pin R14 TEMP 3 R15 Series or shunt mode operation (2.5 V, 3.0 V) R4 4 8 GND O/P SELECT 2.5V DNC DNC = DO NOT CONNECT TO THIS PIN 3.0V GND Figure 1. GENERAL DESCRIPTION The AD780 is an ultrahigh precision band gap reference voltage The AD780 is a pin compatible performance upgrade for the that provides a 2.5 V or 3.0 V output from inputs between 4.0 V LT1019(A)2.5 and the AD680. The latter is targeted toward and 36 V. Low initial error and temperature drift combined with low power applications. low output noise and the ability to drive any value of capacitance The AD780 is available in three grades in PDIP and SOIC make the AD780 the ideal choice for enhancing the performance packages. The AD780AN, AD780AR, AD780BN, AD780BR, of high resolution analog-to-digital converters (ADCs) and and AD780CR are specified for operation from 40C to +85C. digital-to-analog converters (DACs), and for any general-purpose PRODUCT HIGHLIGHTS precision reference application. A unique low headroom design facilitates a 3.0 V output from a 5.0 V 10% input, providing a 1. The AD780 provides a pin programmable 2.5 V or 3.0 V 20% boost to the dynamic range of an ADC over performance output from a 4 V to 36 V input. with existing 2.5 V references. 2. Laser trimming of both initial accuracy and temperature coefficients results in low errors over temperature without The AD780 can be used to source or sink up to 10 mA, and can the use of external components. The AD780BN has a be used in series or shunt mode, thus allowing positive or negative maximum variation of 0.9 mV from 40C to +85C. output voltages without external components. This makes it 3. For applications that require even higher accuracy, an suitable for virtually any high performance reference application. optional fine-trim connection is provided. Unlike some competing references, the AD780 has no region of 4. The AD780 noise is extremely low, typically 4 mV p-p possible instability. The part is stable under all load conditions from 0.1 Hz to 10 Hz and a wideband spectral noise when a 1 F bypass capacitor is used on the supply. density of typically 100 nV/Hz. This can be further A temperature output pin on the AD780 provides an output reduced, if desired, by using two external capacitors. voltage that varies linearly with temperature, allowing the part 5. The temperature output pin enables the AD780 to be to be configured as a temperature transducer while providing a configured as a temperature transducer while providing a stable 2.5 V or 3.0 V output. stable output reference. Rev. H Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 19932015 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 00841-001AD780 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Temperature Output Pin ..............................................................7 Functional Block Diagram .............................................................. 1 Temperature Transducer Circuit .................................................8 General Description ......................................................................... 1 Supply Current Over Temperature .............................................8 Product Highlights ........................................................................... 1 Turn-On Time ...............................................................................8 Revision History ............................................................................... 2 Dynamic Performance ..................................................................9 Specifications ..................................................................................... 3 Line Regulation ..............................................................................9 Absolute Maximum Ratings ............................................................ 4 Precision Reference for High Resolution 5 V Data Converters ................................................................................... 10 Notes ............................................................................................... 4 4.5 V Reference from 5 V Supply ............................................. 10 ESD Caution .................................................................................. 4 Negative (2.5 V) Reference ..................................................... 10 Theory of Operation ........................................................................ 5 Outline Dimensions ....................................................................... 11 Applying the AD780 ......................................................................... 6 Ordering Guide .......................................................................... 12 Noise Performance ....................................................................... 6 Noise Comparison ........................................................................ 7 Temperature Performance ........................................................... 7 REVISION HISTORY 10/15Rev. G to Rev. H Changes to Table 3 ............................................................................ 4 5/04Rev. D to Rev. E Changes to Notes Section ................................................................ 4 Updated Format .................................................................. Universal Changes to Temperature Transducer Circuit Section .................. 8 8/15Rev. F to Rev. G Changes to Ordering Guide .......................................................... 12 Changed NC to DNC .................................................... Throughout Added Solder Heat Shift Parameter, Table 1 ................................. 3 1/04Rev. C to Rev. D Added Table 3, Renumbered Sequentially .................................... 4 Changes to Specifications ................................................................. 2 Changes to Figure 3 .......................................................................... 4 Updated Ordering Guide ................................................................. 3 Change to Notes Section .................................................................. 4 Updated Outline Dimensions ....................................................... 10 Changes to Ordering Guide .......................................................... 12 5/02Rev. B to Rev. C 12/12Rev. E to Rev. F Updates to Packages ....................................................................... 10 Updated Outline Dimensions ....................................................... 11 Changes to Ordering Guide .......................................................... 12 Rev. H Page 2 of 12