16-Bit, 4-Channel/8-Channel, 250 kSPS PulSAR ADCs Data Sheet AD7682/AD7689 FEATURES FUNCTIONAL BLOCK DIAGRAM 2.3V TO 5.5V 0.5V TO VDD 0.5V 0.5V TO VDD 16-bit resolution with no missing codes 0.1F 10F 4-channel (AD7682)/8-channel (AD7689) multiplexer with REFIN REF VDD choice of inputs Unipolar single-ended 1.8V BAND GAP VIO TO REF Differential (GND sense) AD7682/AD7689 VDD Pseudobipolar TEMP SENSOR Throughput: 250 kSPS IN0 CNV INL: 0.4 LSB typical, 1.5 LSB maximum (23 ppm or FSR) IN1 SCK IN2 16-BIT SAR SPI SERIAL MUX Dynamic range: 93.8 dB IN3 ADC INTERFACE SDO IN4 SINAD: 92.5 dB at 20 kHz ONE-POLE IN5 DIN LPF IN6 THD: 100 dB at 20 kHz SEQUENCER IN7 Analog input range: 0 V to V with V up to VDD REF REF COM Multiple reference types GND Internal selectable 2.5 V or 4.096 V External buffered (up to 4.096 V) Figure 1. External (up to VDD) GENERAL DESCRIPTION Internal temperature sensor (TEMP) The AD7682/AD7689 are 4-channel/8-channel, 16-bit, charge Channel sequencer, selectable 1-pole filter, busy indicator redistribution successive approximation register (SAR) analog- No pipeline delay, SAR architecture to-digital converters (ADCs) that operate from a single power Single-supply 2.3 V to 5.5 V operation with 1.8 V to 5.5 V supply, VDD. logic interface Serial interface compatible with SPI, MICROWIRE, QSPI, The AD7682/AD7689 contain all components for use in a and DSP multichannel, low power data acquisition system, including a Power dissipation true 16-bit SAR ADC with no missing codes a 4-channel 3.5 mW at 2.5 V/200 kSPS (AD7682) or 8-channel (AD7689) low crosstalk multiplexer 12.5 mW at 5 V/250 kSPS that is useful for configuring the inputs as single-ended (with or Standby current: 50 nA without ground sense), differential, or bipolar an internal low Low cost grade available drift reference (selectable 2.5 V or 4.096 V) and buffer a 20-lead 4 mm 4 mm LFCSP package temperature sensor a selectable one-pole filter and a sequencer 20-lead 2.4 mm 2.4 mm WLCSP package that is useful when channels are continuously scanned in order. APPLICATIONS The AD7682/AD7689 use a simple serial port interface (SPI) for writing to the configuration register and receiving conversion Multichannel system monitoring results. The SPI interface uses a separate supply, VIO, which is set Battery-powered equipment to the host logic level. Power dissipation scales with throughput. Medical instruments: ECG/EKG Mobile communications: GPS Continued on Page 4 Power line monitoring Data acquisition Seismic data acquisition systems Instrumentation Process control Rev. J 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 20082019 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. 07353-001AD7682/AD7689 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Voltage Reference Output/Input .............................................. 26 Applications ....................................................................................... 1 Power Supply ............................................................................... 28 Functional Block Diagram .............................................................. 1 Supplying the ADC from the Reference .................................. 28 General Description ......................................................................... 1 Digital Interface .............................................................................. 29 Revision History ............................................................................... 2 Reading/Writing During Conversion, Fast Hosts .................. 29 Specifications ..................................................................................... 5 Reading/Writing After Conversion, Any Speed Hosts .......... 29 Timing Specifications .................................................................. 9 Reading/Writing Spanning Conversion, Any Speed Host .... 29 Absolute Maximum Ratings .......................................................... 12 Configuration Register, CFG .................................................... 29 ESD Caution ................................................................................ 12 General Timing Without a Busy Indicator ............................. 31 Pin Configurations and Function Descriptions ......................... 13 General Timing with a Busy Indicator .................................... 32 Typical Performance Characteristics ........................................... 17 Channel Sequencer .................................................................... 33 Terminology .................................................................................... 20 Read/Write Spanning Conversion Without a Busy Indicator ...................................................................................... 34 Theory of Operation ...................................................................... 21 Read/Write Spanning Conversion with a Busy Indicator ..... 35 Overview ...................................................................................... 21 Applications Information .............................................................. 36 Converter Operation .................................................................. 21 Layout .......................................................................................... 36 Transfer Functions...................................................................... 22 Evaluating the AD7682/AD7689 Performance ........................ 36 Typical Connection Diagrams .................................................. 23 Outline Dimensions ....................................................................... 37 Analog Inputs .............................................................................. 24 Ordering Guide .......................................................................... 38 Driver Amplifier Choice ............................................................ 26 REVISION HISTORY 11/2019Rev. I to Rev. J Changes to Ordering Guide .......................................................... 35 Updated Outline Dimensions ....................................................... 37 4/2016Rev. E to Rev. F 11/2019Rev. H to Rev. I Changed ADA4841-x to ADA4805-1/ADA4807-1, Table 1 ........ 1 Changes to General Description Section ...................................... 4 Added Endnote 6, Table 3 Renumbered Sequentially ................. 6 Changes to Table 2 ............................................................................ 5 Changes to Figure 28 and Figure 29 ............................................ 20 Added Table 3 Renumbered Sequentially .................................... 7 Changes to Table 10 ....................................................................... 23 Changes to Table 4 ............................................................................ 8 Changes to External Reference Section and the Reference Changes to Timing Specifications Section .................................... 9 Decoupling Section ........................................................................ 24 Changes to Table 6 .......................................................................... 10 Changes to the Supplying the ADC from the Reference Section .. 25 Changes to Pin 1, Pin 20 Description, Table 8 ............................ 13 Changes to Ordering Guide .......................................................... 35 Changes to Pin B6, Pin B8 Description, Table 9......................... 15 Changes to Figure 38 ...................................................................... 28 1/2015Rev. D to Rev. E Updated Outline Dimensions ....................................................... 37 Added WLCSP (Throughout) ......................................................... 1 Changes to Ordering Guide .......................................................... 38 Added WLCSP Signal-to-Noise and SINAD Parameters Table 2 .................................................................................................3 8/2017Rev. G to Rev. H Changed JA Thermal Impedance (LFCSP) from 47.6C/W to Changed CP-20-8 to CP-20-10 .................................... Throughout 48C/W ...............................................................................................9 Change to Product Title ................................................................... 1 Added Figure 6, Figure 7, and Table 8 ......................................... 12 Updated Outline Dimensions ....................................................... 34 Changes to Layout Section ............................................................ 33 Changes to Ordering Guide .......................................................... 35 Added Figure 47 Outline Dimensions ........................................ 34 Changes to Ordering Guide .......................................................... 35 6/2017Rev. F to Rev. G Changed CP-20-10 to CP-20-8 .................................... Throughout Changes to Table 11 ........................................................................ 27 Updated Outline Dimensions ....................................................... 34 Rev. J Page 2 of 38