AD7984_15 Datasheet, PDF (1/24 Pages) Analog Devices – 18-Bit, 1.33 MSPS PulSAR 10.5 mW ADC in MSOP/LFCSP

Data Sheet
18-Bit, 1.33 MSPS PulSAR 10.5 mW
ADC in MSOP/LFCSP
AD7984
FEATURES
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
Dynamic range: 99.7 dB typical
True differential analog input range: ±VREF
0 V to VREF with VREF between 2.9 V to 5.0 V
Allows use of any input range
Easy to drive with the ADA4941
No pipeline delay
Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic
interface
Proprietary serial interface
SPI/QSPI/MICROWIRE™/DSP compatible
Ability to daisy-chain multiple ADCs and busy indicator
10-lead MSOP (MSOP-8 size) and 10-lead 3 mm × 3 mm
LFCSP, SOT-23 size
APPLICATIONS
Battery-powered equipment
Data acquisition systems
Medical instruments
Seismic data acquisition systems
APPLICATION DIAGRAM
2.9V TO 5V 2.5V
±10V, ±5V, ..
ADA4941
REF VDD ^VIO
IN+
SDI
AD7984 SCK
IN–
GND
SDO
CNV
1.8V TO 5V
3- OR 4-WIRE
INTERFACE
(SPI, CS
DAISY CHAIN)
Figure 1.
GENERAL DESCRIPTION
The AD7984¹ is an 18-bit, successive approximation, analog-to-
digital converter (ADC) that operates from a single power
supply, VDD. It contains a low power, high speed, 18-bit
sampling ADC and a versatile serial interface port. On the CNV
rising edge, the AD7984 samples the voltage difference between
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
supply voltage, VDD.
The SPI-compatible serial interface also features the ability,
using the SDI input, to daisy-chain several ADCs on a single
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
14-Bit
AD7940
AD7942¹
16-Bit
AD7680
AD7685¹
AD7683
AD7687¹
AD7684
AD7694
AD7988-1
18-Bit
AD7989-1
AD7691¹
1 _{Pin-for-pin compatible.}
400 kSPS to 500 kSPS
AD7946¹
AD7686¹
AD7688¹
AD7693¹
AD7988-5
AD7690¹
AD7989-5
≥1000 kSPS
AD7980¹
AD7983¹
AD7982¹
AD7984¹
ADC Driver
ADA4941-x
ADA4841-x
ADA4941-x
ADA4841-x
Rev. B
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