32-Channel, 24-Bit Current-to-Digital ADC

Data Sheet

ADAS1126

Rev. SpC

Document Feedback

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

responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother

rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.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

©2010-2013 Analog Devices, Inc. All rights reserved.

Technical Support

www.analog.com

FEATURES

32-channel, low level current-to-digital converter

Up to 24-bit resolution

Up to 19.7 kSPS (50.7 µs integration time)

Simultaneous sampling

User-adjustable full-scale range

INL: ±0.025% of reading ±0.75 ppm of FSR

Very low power dissipation: 12.5 mW/channel

LVDS self-clocked serial data interface

SPI configuration registers (daisy-chain)

On-board temperature sensor and reference buffer

10 mm × 10 mm, mini-BGA package

Low cost external components

Support tools

Evaluation board

Reference design with reference layout

FPGA Verilog code

APPLICATIONS

Medical, industrial, and security CT scanner data acquisition

Photodiode sensors

Dosimetry and radiation therapy systems

Optical fiber power monitoring

X-ray detection systems

High channel-count data acquisition systems (current or

voltage inputs)

GENERAL DESCRIPTION

The ADAS1126 is a 32-channel, current-to-digital, analog-to-

digital converter (ADC). It contains 32 low power, low noise,

low input current integrators, simultaneous sample-and-holds,

and a high speed, high resolution ADCs with configurable

sampling rate and resolutions up to 24 bits.

All converted channel results are output on a single LVDS self-

clocked serial interface, which reduces external hardware.

An SPI-compatible serial interface allows configuration of the

ADC using the SDI input. The SDO output allows the user to

daisy-chain several ADCs on a single, 3-wire bus. The

ADAS1126 uses the separate supply IOVDD to reduce the

digital noise effect on the conversions.

The ADAS1126 is in a 10 mm × 10 mm, mini-BGA package.

FUNCTIONAL BLOCK DIAGRAM

ADCH

AN16

AN31

REF

BUFP

S/H

S/H

OR(0:31)

AN0

AN15

S/H

S/H

DOUTx

SDI

SDO

SCK

CS

CLKx

SYNC

IOVDD

IOGND

+

–

FROM PREVIOUS

SDO

TO NEXT SDI

TO ALL ADCs

2.5V

2.048V

RESET

FROM DOUT OF

OTHER ADCs

BUFN

KGND

2.5V 3.3V

DATA

PROCESSING

F

OR0

F

OR15

F

OR16

F

OR31

CONFIGURATION

LVDS/CMOS

INTERFACE

SDI

SDI

TEMP

FPGA

VIO

Figure 1.

For more information about the ADAS1126, email: adas@analog.com.