18-Bit, 1.33 MSPS PulSAR 10.5 mW

ADC in MSOP/QFN

AD7984

Rev. 0

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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

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

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 QFN

(LFCSP), SOT-23 size

APPLICATIONS

Battery-powered equipment

Data acquisition systems

Medical instruments

Seismic data acquisition systems

APPLICATION DIAGRAM

AD7984

REF

GND

VDD

IN+

IN–

VIO

SDI

SCK

SDO

CNV

1.8V TO 5V

ADA4941

3- OR 4-WIRE

INTERFACE

(SPI, CS

DAISY CHAIN)

2.9V TO 5V 2.5V

±10V, ±5V, ..

Figure 1.

GENERAL DESCRIPTION

The AD7984 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

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 QFN

(LFCSP) with operation specified from −40°C to +85°C.

Table 1. MSOP, QFN (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

18-Bit

AD76911

AD76901

AD79821

ADA4941-x

AD79841

ADA4841-x