AD7694

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother

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.Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

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

Tel: 781.329.4700

www.analog.com

Fax: 781.461.3113

© 2005 Analog Devices, Inc. All rights reserved.

FEATURES

16-bit resolution with no missing codes

Throughput: 250 kSPS @ 5 V

INL: ±4 LSB max

S/(N + D): 92 dB @ 20 kHz

THD: –106 dB @ 20 kHz

Pseudo-differential analog input range:

No pipeline delay

Single-supply operation: 2.7 V or 5 V

Serial interface SPI®/QSPI™/MICROWIRE™/DSP-compatible

Supply Current: 540 μA @ 2.7 V/100 kSPS,

800 μA @ 5 V/100 kSPS

Standby current: 1 nA

8-lead MSOP package

Improved second source to LTC1864 and LTC1864L

APPLICATIONS

Battery-powered equipment

Data acquisition

Instrumentation

Medical instruments

Process control

GENERAL DESCRIPTION

The AD7694 is a 16-bit, charge redistribution, successive

approximation, PulSAR analog-to-digital converter (ADC) that

operates from a single power supply, VDD, between 2.7 V to

5.25 V. It contains a low power, high speed, 16-bit sampling

ADC with no missing codes (B grade), an internal conversion

clock, and a serial, SPI-compatible interface port. The part also

contains a low noise, wide bandwidth, short aperture delay

track-and-hold circuit. On the CNV rising edge, it samples an

analog input, IN+, between 0 V to REF with respect to a ground

sense, IN−. The reference voltage, REF, is applied externally and

can be set up to the supply voltage.

Its power scales linearly with throughput.

The AD7694 is housed in an 8-lead MSOP package with an

operating temperature specified from −40°C to +85°C.

APPLICATION DIAGRAM

AD7694

REF

GND

VDD

IN+

IN–

SCK

SDO

CNV

3-WIRE SPI

INTERFACE

1V TO VDD

2.5V TO 5V

Figure 1.

Table 1. MSOP, LFCSP (QFN)/SOT-23, 16-Bit PulSAR ADC

Type

100 kSPS

250 kSPS

500 kSPS

True Differential

AD7684

AD7687

AD7688

Pseudo

AD7683

AD7685

AD7686

Differential/Unipolar

AD7694

Unipolar

AD7680