18-Bit, 2.5 LSB INL, 800 kSPS SAR ADC

AD7674

Rev. 0

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 companies.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

Fax: 781.326.8703

© 2003 Analog Devices, Inc. All rights reserved.

FEATURES

18-bit resolution with no missing codes

No pipeline delay (SAR architecture)

Throughput: 800 kSPS (Warp mode)

666 kSPS (Normal mode)

570 kSPS (Impulse mode)

INL: ±2.5 LSB max (±9.5 ppm of full scale)

Parallel (18-,16-, or 8-bit bus) and serial 5 V/3 V interface

SPI

On-board reference buffer

Single 5 V supply operation

Power dissipation:98 mW typ @ 800 kSPS

78 mW typ@ 500 kSPS (Impulse mode)

160 µW @ 1 kSPS (Impulse mode)

48-lead LQFP or 48-lead LFCSP package

Pin-to-pin compatible upgrade of AD7676/AD7678/AD7679

APPLICATIONS

CT scanners

High dynamic data acquisition

Geophone and hydrophone sensors

Instrumentation

Spectrum analysis

Medical instruments

GENERAL DESCRIPTION

The AD7674 is an 18-bit, 800 kSPS, charge redistribution SAR,

fully differential analog-to-digital converter that operates on a

single 5 V power supply. The part contains a high speed 18-bit

sampling ADC, an internal conversion clock, an internal

reference buffer, error correction circuits, and both serial and

parallel system interface ports.

The part is available in 48-lead LQFP or 48-lead LFCSP

packages with operation specified from –40°C to +85°C.

FUNCTIONAL BLOCK DIAGRAM

SWITCHED

CAP DAC

18

CONTROL LOGIC AND

CALIBRATION CIRCUITRY

CLOCK

AD7674

D[17:0]

BUSY

RD

CS

MODE0

OGND

OVDD

DGND

DVDD

AVDD

AGND

REF REFGND

IN+

IN–

PD

RESET

SERIAL

PORT

PARALLEL

INTERFACE

CNVST

PDBUF

REFBUFIN

WARP IMPULSE

MODE1

03083–0–001

Figure 1. Functional Block Diagram

Type/kSPS

100–250

500–570

800–

1000

Pseudo-

Differential

AD7651

AD7660/AD7661

AD7650/AD7652

AD7664/AD7666

AD7653

AD7667

True Bipolar

AD7663

AD7665

AD7671

True

Differential

AD7675

AD7676

AD7677

18-Bit

AD7678

AD7679

AD7674

Multichannel/

Simultaneous

AD7654

AD7655

PRODUCT HIGHLIGHTS

1.

High Resolution, Fast Throughput.

The AD7674 is an 800 kSPS, charge redistribution, 18-bit

SAR ADC (no latency).

2.

Excellent Accuracy.

The AD7674 has a maximum integral nonlinearity of

2.5 LSB with no missing 18-bit codes.

3.

Serial or Parallel Interface.

Versatile parallel (18-, 16- or 8-bit bus) or 3-wire serial

interface arrangement compatible with both 3 V and

5 V logic.