AD7988-1_1208 AD [Analog Devices], AD7988-1_1208 Datasheet

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AD7988-1_1208

Manufacturer Part Number
AD7988-1_1208
Description
16-Bit Lower Power PulSAR ADCs in MSOP/LFCSP (QFN)
Manufacturer
AD [Analog Devices]
Datasheet
Data Sheet
FEATURES
Low power dissipation
16-bit resolution with no missing codes
Throughput: 100 kSPS/500 kSPS options
INL: ±0.6 LSB typical, ±1.25 LSB maximum
SINAD: 91.5 dB @ 10 kHz
THD: −114 dB @ 10 kHz
Pseudo differential analog input range
No pipeline delay
Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic
SPI-/QSPI-/MICROWIRE™-/DSP-compatible serial interface
Daisy-chain multiple ADCs
10-lead MSOP and 10-lead, 3 mm × 3 mm LFCSP (QFN), same
Wide operating temperature range: −40°C to +125°C
APPLICATIONS
Battery-powered equipment
Low power data acquisition systems
Portable medical instruments
ATE equipment
Data acquisitions
Communications
Rev. C
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 or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
AD7988-5: 3.5 mW @ 500 kSPS
AD7988-1: 700 µW @ 100 kSPS
0 V to V
Any input range and easy to drive with the
interface
space as SOT-23
REF
with V
REF
from 2.5 V to 5.5 V
0V TO V
REF
ADA4841-1
TYPICAL APPLICATION DIAGRAM
2.5V TO 5V
IN+
IN–
AD7988-1/
AD7988-5
GND
REF
2.5V
VDD
PulSAR ADCs in MSOP/LFCSP (QFN)
Figure 1.
SDO
SCK
CNV
VIO
SDI
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
GENERAL DESCRIPTION
The
analog-to-digital converters (ADC) that operate from a single
power supply, VDD. The
and the
power, 16-bit sampling ADCs with a versatile serial interface
port. On the CNV rising edge, they sample an analog input,
IN+, between 0 V to V
The reference voltage, REF, is applied externally and can be set
independent of the supply voltage, VDD.
The SPI-compatible serial interface also features the ability to
daisy-chain several ADCs on a single 3-wire bus using the SDI
input. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic using
the separate supply, VIO.
The
MSOP or a 10-lead LFCSP (QFN) with operation specified
from −40°C to +125°C.
Table 1. MSOP, LFCSP (QFN) 14-/16-/18-Bit PulSAR® ADCs
Bits
18
16
16
14
1
2
3
True differential.
Pin-for-pin compatible.
Pseudo differential.
1
3
1
3
AD7988-1/AD7988-5
AD7988-1/AD7988-5
1.8V TO 5.5V
3- OR 4-WIRE INTERFACE
(SPI, DAISY CHAIN, CS)
100 kSPS
AD7684
AD7680
AD7683
AD7988-1
AD7940
AD7988-5
2
offers a 500 kSPS throughput. They are low
250 kSPS
AD7691
AD7687
AD7685
AD7694
AD7942
AD7988-1/AD7988-5
16-Bit Lower Power
REF
©2012 Analog Devices, Inc. All rights reserved.
AD7988-1
are 16-bit, successive approximation,
with respect to a ground sense, IN−.
generics are housed in a 10-lead
2
2
2
2
400 kSPS to
500 kSPS
AD7690
AD7688
AD7693
AD7686
AD7988-5
AD7946
offers a 100 kSPS throughput,
2
2
2
2
2
2
≥1000
kSPS
AD7982
AD7984
AD7980
www.analog.com
2
2
2
ADC Driver
ADA4941-1
ADA4841-1
ADA4941-1
ADA4841-1
ADA4841-1
ADA4841-1
ADA4841-1
ADA4841-1

Related parts for AD7988-1_1208

AD7988-1_1208 Summary of contents

Page 1

... Data Sheet FEATURES Low power dissipation AD7988-5: 3 500 kSPS AD7988-1: 700 µW @ 100 kSPS 16-bit resolution with no missing codes Throughput: 100 kSPS/500 kSPS options INL: ±0.6 LSB typical, ±1.25 LSB maximum SINAD: 91 kHz THD: −114 kHz Pseudo differential analog input range ...

Page 2

... Analog Inputs.............................................................................. 16 Driver Amplifier Choice ........................................................... 16 Voltage Reference Input ............................................................ 17 Power Supply ............................................................................... 17 Digital Interface .......................................................................... 17 CS Mode, 3-Wire ........................................................................ 18 CS Mode 4-Wire ......................................................................... 19 Chain Mode ................................................................................ 20 Applications Information .............................................................. 21 Interfacing to Blackfin® DSP ..................................................... 21 Layout .......................................................................................... 21 Evaluating the Performance of the AD7988-x ........................ 21 Outline Dimensions ....................................................................... 22 Ordering Guide .......................................................................... 23 Rev Page Data Sheet ...

Page 3

... REF kHz 2 REF kHz kHz kHz REF kHz 2 REF Rev Page AD7988-1/AD7988-5 Min Typ Max Unit 16 Bits REF −0 0.1 V REF −0.1 +0 See the Analog Inputs section ...

Page 4

... VIO Specified performance VIO Range Standby Current 1, 2 VDD and VIO = 2.5 V, 25°C AD7988-1 Power Dissipation 10 kSPS throughput 100 kSPS throughput AD7988-5 Power Dissipation 500 kSPS throughput Energy per Conversion TEMPERATURE RANGE Specified Performance MIN 1 With all digital inputs forced to VIO or GND as required. ...

Page 5

... SCK t SCK t SCKL t SCKH t HSDO t DSDO DIS t SSDICNV t HSDICNV t HSDICNV t SSCKCNV t HSCKCNV t SSDISCK t HSDISCK Rev Page AD7988-1/AD7988-5 Min Typ Max Unit 100 kHz 9.5 μs 500 ns 10 μs 500 kHz 1.6 μs 400 ns 2 μs 500 ns 10 ...

Page 6

... AD7988-1/AD7988-5 500µ SDO C L 20pF 500µ Figure 2. Load Circuit for Digital Interface Timing Y% VIO 1 X% VIO t DELAY FOR VIO ≤ 3.0V AND Y = 10; FOR VIO > 3. 70, AND MINIMUM V AND MAXIMUM V USED. SEE DIGITAL INPUTS ...

Page 7

... V or ±130 mA REF other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION Rev Page AD7988-1/AD7988-5 ...

Page 8

... SDO CNV range is from 2 5 referred to the GND pin. The GND pin REF . REF Rev Page Data Sheet REF 1 10 VIO AD7988-1/ VDD 2 9 SDI AD7988-5 IN SCK TOP VIEW IN– SDO (Not to Scale) GND 5 6 CNV NOTES 1 ...

Page 9

... CNV input and when the input signal is held for a conversion. Transient Response Transient response is the time required for the ADC to accurately acquire its input after a full-scale step function is applied. N /Peak-to-Peak Noise) Rev Page AD7988-1/AD7988 /RMS Input Noise) 2 ...

Page 10

... SNR = 86.7dB THD = –110.4dB –40 SFDR = 103.9dB SINAD = 86.6dB –60 –80 –100 –120 –140 –160 –180 FREQUENCY (kHz) Figure 9. AD7988-1 FFT Plot 2.5 V REF 1.25 POSITIVE INL: +0.40 LSB NEGATIVE INL: –0.35 LSB 1.00 0.75 0.50 0. 16384 32768 49152 CODE Figure 10. Integral Nonlinearity vs. Code ...

Page 11

... V Figure 17. Histogram Input at the Code Center, V REF Rev Page AD7988-1/AD7988-5 50970 45198 18848 12424 1217 2290 7FFA 7FFB 7FFC 7FFD 7FFE 7FFF 8000 8001 8002 8003 8004 8005 8006 CODE IN HEX 2 ...

Page 12

... TEMPERATURE (°C) Figure 21. SNR vs. Temperature I VDD I REF I VIO 0 2.425 2.475 2.525 2.575 VDD VOLTAGE (V) Figure 22. Operating Currents vs. Supply (AD7988-5) I VDD I REF I VIO 0 2.375 2.425 2.475 2.525 2.575 VDD VOLTAGE (V) Figure 23. Operating Currents vs. Supply (AD7988-1) 105 125 2.625 2.625 ...

Page 13

... TEMPERATURE (°C) Figure 25. THD vs. Temperature 0.7 I VDD 0.6 0.5 0.4 0.3 I REF 0.2 I VIO 0.1 0 –55 –35 – TEMPERATURE (°C) Figure 26. Operating Currents vs. Temperature (AD7988- 105 125 65 85 105 125 Rev Page AD7988-1/AD7988-5 0.14 I VDD 0.12 0.10 008 0.06 I REF 0.04 I VIO 0.02 0 –55 –35 –15 ...

Page 14

... The AD7988-x can be interfaced to any 1 digital logic family housed in a 10-lead MSOP or a tiny 10-lead LFCSP (QFN) that combines space savings and allows flexible configurations ...

Page 15

... Digital Output Code (Hex) REF 4.999924 V FFFF 1 2.500076 V 8001 2.5 V 8000 2.499924 V 7FFF 76.3 µV 0001 0000 − V IN+ IN− IN+ AD7988-x when multiple supplies are available. 2.5V 100nF 1.8V TO 5.5V 100nF VIO SDI SCK 3- OR 4-WIRE INTERFACE SDO CNV above V − REF GND − V below V ). ...

Page 16

... AD7988-x is easy to drive, the driver amplifier The noise generated by the driver amplifier must be kept as low as possible to preserve the SNR and transition noise performance of the AD7988-x. The noise coming from the driver is filtered by the AD7988-x analog input circuit’s one-pole, low-pass filter made by R ...

Page 17

... DIGITAL INTERFACE Although the flexibility in its serial interface modes. The AD7988-x, when in CS mode, is compatible with SPI, QSPI™, and digital hosts. This interface can use either a 3-wire or 4-wire ADR43x reference. interface. A 3-wire interface using the CNV, SCK, and SDO signals minimizes wiring connections and is useful, for instance, in isolated applications ...

Page 18

... After the 16th SCK falling edge or when CNV goes high, whichever is earlier, SDO returns to high impedance. enters the CONVERT DIGITAL HOST CNV VIO AD7988-1/ SDI SDO DATA IN AD7988-5 SCK CLK Figure 34. 3-Wire CS Mode Connection Diagram t CYC t CNVH t ACQ ACQUISITION ...

Page 19

... SCKL HSDO SCKH t DSDO D15 D14 D13 D1 D0 Figure 37. 4-Wire CS Mode Serial Interface Timing Rev Page AD7988-1/AD7988-5 AD7988-x CS2 CS1 CONVERT DIGITAL HOST SDO DATA IN CLK D15 D14 D1 enters the AD7988-x t DIS ...

Page 20

... SCK falling edge allows a faster reading rate and, consequently, more AD7988-x has an acceptable hold time. The maximum conversion rate may be reduced due to the total readback time. CNV AD7988-1/ SDO SDI AD7988-5 B SCK Figure 38. Chain Mode Connection Diagram ...

Page 21

... Design the printed circuit board (PCB) that houses the so that the analog and digital sections are separated and confined to certain areas of the board. The pinout of the AD7988-x, with all the analog signals on the left side and all the digital signals on the right side, eases this task. ...

Page 22

... AD7988-1/AD7988-5 OUTLINE DIMENSIONS IDENTIFIER PIN 1 INDEX AREA 0.80 0.75 0.70 SEATING PLANE 3.10 3.00 2.90 5. 3.10 4.90 3.00 4.65 1 2.90 5 PIN 1 0.50 BSC 0.95 15° MAX 0.85 1.10 MAX 0.75 0.15 0.23 6° 0.30 0.05 0.13 0° 0.15 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-BA Figure 44.10-Lead Mini Small Outline Package [MSOP] (RM-10) Dimensions shown in millimeters 3.10 3.00 SQ 2.90 6 0.50 0.40 0.30 5 TOP VIEW 0.05 MAX 0.02 NOM COPLANARITY 0.08 0.30 0.20 REF ...

Page 23

... Reel, 5,000 10-Lead QFN (LFCSP_WD) −40°C to +125°C Reel, 1,500 10-Lead QFN (LFCSP_WD) Evaluation Board with AD7988-5 Populated; Use for Evaluation of Both AD7988-1 and AD7988-5. System Demonstration Board, Used as a Controller Board for Data Transfer via USB Interface to PC. ...

Page 24

... AD7988-1/AD7988-5 NOTES ©2012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D10231-0-8/12(C) Rev Page Data Sheet ...

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