Datasheet AD7984 (Analog Devices)

18-Bit, 1.33 MSPS PulSAR 10.5 mW ADC in MSOP/LFCSP Data Sheet AD7984 FEATURES APPLICATION DIAGRAM 2.9V TO 5V 2.5V 18-bit resolution with no missing codes Throughput: 1.33 MSPS Low power dissipation: 10.5 mW at 1.33 MSPS INL: ±2.25 LSB maximum REF VDD VIO 1.8V TO 5V IN+ SDI Dynamic range: 99.7 dB typical 3- OR 4-WIRE AD7984 SCK INTERFACE True differential analog input range: ±V ±10V, ±5V, .. REF IN– SDO (SPI, CS 0 V to V GND DAISY CHAIN) REF with VREF between 2.9 V to 5.0 V CNV ADA4941
01 0
Allows use of any input range
73- 69 0
Easy to drive with the ADA4941
Figure 1.
No pipeline delay GENERAL DESCRIPTION Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface
The AD79841 is an 18-bit, successive approximation, analog-to-
Proprietary serial interface
digital converter (ADC) that operates from a single power
SPI/QSPI/MICROWIRE™/DSP compatible
supply, VDD. It contains a low power, high speed, 18-bit
Ability to daisy-chain multiple ADCs and busy indicator
sampling ADC and a versatile serial interface port. On the CNV
10-lead MSOP (MSOP-8 size) and 10-lead 3 mm × 3 mm
rising edge, the AD7984 samples the voltage difference between
LFCSP, SOT-23 size
the IN+ and IN− pins. The voltages on these pins usually swing

in opposite phases between 0 V and VREF. The reference voltage, REF, is applied externally and can be set independent of the
APPLICATIONS
supply voltage, VDD.
Battery-powered equipment
The SPI-compatible serial interface also features the ability,
Data acquisition systems
using the SDI input, to daisy-chain several ADCs on a single
Medical instruments Seismic data acquisition systems
3-wire bus and provides an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply. The AD7984 is available in a 10-lead MSOP or a 10-lead LFCSP with operation specified from −40°C to +85°C. 1 Protected by U.S. Patent 6,703,961.
Table 1. MSOP, LFCSP 14-/16-/18-Bit PulSAR® ADC Type 100 kSPS 250 kSPS 400 kSPS to 500 kSPS ≥1000 kSPS ADC Driver
14-Bit AD7940 AD79421 AD79461 16-Bit AD7680 AD76851 AD76861 AD79801 ADA4941-x AD7683 AD76871 AD76881 AD79831 ADA4841-x AD7684 AD7694 AD76931 AD7988-1 AD7988-5 18-Bit AD7989-1 AD76911 AD76901 AD79821 ADA4941-x AD7989-5 AD79841 ADA4841-x 1 Pin-for-pin compatible.
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Document Outline FEATURES APPLICATIONS APPLICATION DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER OPERATION Transfer Functions TYPICAL CONNECTION DIAGRAM ANALOG INPUTS DRIVER AMPLIFIER CHOICE SINGLE-TO-DIFFERENTIAL DRIVER VOLTAGE REFERENCE INPUT POWER SUPPLY DIGITAL INTERFACE MODE, 3-CS WIRE WITHOUT BUSY INDICATOR CS MODE, 3-WIRE WITH BUSY INDICATOR CS MODE, 4-WIRE WITHOUT BUSY INDICATOR CS MODE, 4-WIRE WITH BUSY INDICATOR CHAIN MODE WITHOUT BUSY INDICATOR CHAIN MODE WITH BUSY INDICATOR APPLICATION HINTS LAYOUT EVALUATING THE AD7984 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE