16-Bit, 500 kSPS PulSAR ADC in MSOP Data Sheet AD7686 FEATURES FUNCTIONAL BLOCK DIAGRAM 0.5V TO 5V 5V 16-bit resolution with no missing codes Throughput: 500 kSPS INL: 0.6 LSB typical, 2 LSB maximum (0.003% of FSR) SINAD: 92.5 dB at 20 kHz VIO 1.8V TO VDD REF VDD 0 TO VREF SDI THD: 110 dB at 20 kHz IN+ SCK AD7686 3- OR 4-WIRE INTERFACE Pseudo differential analog input range IN (SPI, DAISY CHAIN, CS) SDO 0 V to V with V up to VDD GND REF REF CNV No pipeline delay Single-supply 5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface Figure 2. Proprietary serial interface: SPI-/QSPI-/MICROWIRE-/DSP- compatible Table 1. MSOP, LFCSP/SOT-23 14-/16-/18-Bit PulSAR ADC Daisy-chain multiple ADCs and busy indicator 400 kSPS 100 250 to 1000 ADC Power dissipation Type kSPS kSPS 500 kSPS kSPS Driver 3.75 W at 5 V/100 SPS 18-Bit True AD7691 AD7690 AD7982 ADA4941 3.75 mW at 5 V/100 kSPS Differential AD7982 ADA4941 Standby current: 1 nA 16-Bit True AD7684 AD7687 AD7688 ADA4941 10-lead MSOP (MSOP-8 size) and Differential AD7693 ADA4841 3 mm 3 mm, 10-lead LFCSP (SOT-23 size) 16-Bit Pseudo AD7680 AD7685 AD7686 AD7980 ADA4941 Pin-for-pin-compatible with 10-lead MSOP/PulSAR ADCs Differential AD7683 AD7694 14-Bit Pseudo AD7940 AD7942 AD7946 ADA4941 APPLICATIONS Differential Battery-powered equipment Data acquisitions GENERAL DESCRIPTION Instrumentation 1 The AD7686 is a 16-bit, charge redistribution, successive Medical instruments approximation, analog-to-digital converter (ADC) that operates Process controls from a single 5 V power supply, VDD. It contains a low power, 2.0 high speed, 16-bit sampling ADC with no missing codes, an POSITIVE INL = +0.52LSB NEGATIVE INL = 0.38LSB internal conversion clock, and a versatile serial interface port. 1.5 The part also contains a low noise, wide bandwidth, short 1.0 aperture delay track-and-hold circuit. On the CNV rising edge, the AD7686 samples an analog input IN+ between 0 V to REF 0.5 with respect to a ground sense IN. The reference voltage, REF, 0 is applied externally and can be set up to the supply voltage. Power dissipation scales linearly with throughput. 0.5 The SPI-compatible serial interface also features the ability, 1.0 using the SDI input, to daisy-chain several ADCs on a single, 3-wire bus or provides an optional busy indicator. This device is 1.5 compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate 2.0 supply VIO. 0 16384 32768 49152 65535 CODE The AD7686 is housed in a 10-lead MSOP or a 10-lead LFCSP with operation specified from 40C to +85C. Figure 1. Integral Nonlinearity vs. Code 1. Protected by U.S. Patent 6,703,961. Rev. C 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 20052014 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com INL (LSB) 02969-007 02969-002AD7686 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Driver Amplifier Choice ........................................................... 15 Applications ....................................................................................... 1 Voltage Reference Input ............................................................ 15 Functional Block Diagram .............................................................. 1 Power Supply ............................................................................... 15 General Description ......................................................................... 1 Supplying the ADC from the Reference .................................. 16 Revision History ............................................................................... 2 Digital Interface .......................................................................... 16 Specifications ..................................................................................... 3 CS MODE 3-Wire, No Busy Indicator .................................... 17 Timing Specifications ....................................................................... 5 CS Mode 3-Wire with Busy Indicator ..................................... 18 Absolute Maximum Ratings ............................................................ 6 CS Mode 4-Wire, No Busy Indicator ....................................... 19 ESD Caution .................................................................................. 6 CS Mode 4-Wire with Busy Indicator ..................................... 20 Pin Configurations and Function Descriptions ........................... 7 Chain Mode, No Busy Indicator .............................................. 21 Terminology ...................................................................................... 8 Chain Mode with Busy Indicator ............................................. 22 Typical Performance Characteristics ............................................. 9 Application Hints ........................................................................... 23 Theory of Operation ...................................................................... 12 Layout .......................................................................................... 23 Circuit Information .................................................................... 12 Evaluating the Performance of the AD7686 ............................ 23 Converter Operation .................................................................. 12 True 16-Bit Isolated Application Example .............................. 24 Typical Connection Diagram.................................................... 13 Outline Dimensions ....................................................................... 25 Analog Input ............................................................................... 14 Ordering Guide .......................................................................... 26 REVISION HISTORY 4/06Rev. 0 to Rev. A 8/14Rev. B to Rev. C Deleted QFN .................................................................. Throughout Updated Format .................................................................. Universal Change to Features Section ............................................................. 1 Updated Outline Dimensions ....................................................... 25 Added Patent Note, Note 1 .............................................................. 1 Changes to Ordering Guide .......................................................... 26 Added EPAD Notation to Figure 6 and Table 6............................ 7 Changes to Evaluating the Performance of the AD7686 4/05Revision 0: Initial Version Section .............................................................................................. 23 Updated Outline Dimensions ....................................................... 25 Changes to Ordering Guide .......................................................... 26 3/07Rev. A to Rev. B Changes to Features and Table 1..................................................... 1 Changes to Table 3 ............................................................................ 4 Moved Figure 3 and Figure 4 to Page ............................................. 5 Changes to Figure 13 and Figure 15 ............................................. 10 Changes to Figure 26 ...................................................................... 13 Changes to Table 8 .......................................................................... 15 Changes to Figure 31 ...................................................................... 16 Changes to Figure 42 ...................................................................... 21 Changes to Figure 44 ...................................................................... 22 Updated Outline Dimensions ....................................................... 25 Changes to Ordering Guide .......................................................... 26 Rev. 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