Serial

Interface

DVALID

DCLK

DOUT

DIN

Configuration

and

Control

IN2

IN1

DGND

AGND

IN4

IN3

IN30

IN29

DS

ADC

IN32

IN31

CLK

CONV

DIN_CFG

CLK_CFG

RESET

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

Dual

Switched

Integrator

VREF

DVDD

AVDD

0.1 F

m

0.1 F

m

0.1 F

m

DS

ADC

DS

ADC

DS

ADC

DDC232

www.ti.com

SBAS331D – AUGUST 2004 – REVISED APRIL 2010

32-Channel, Current-Input

Analog-to-Digital Converter

Check for Samples: DDC232

The DDC232 uses a +5V analog supply and a +2.7V

1

FEATURES

to

+3.6V

digital

supply.

Operating

over

the

2

•

Single-Chip Solution to Directly Measure 32

temperature range of 0°C to +70°C, the DDC232

Low-Level Currents

BGA-64 package is offered in two versions: the

•

High-Precision, True Integrating Function

DDC232C

for

low-power

applications,

and

the

DDC232CK when higher speeds are required.

•

Integral Linearity:

±0.025% of Reading ±1.0ppm of FSR

•

Very Low Noise: 5.3ppm of FSR

•

Low Power: 7mW/channel

•

Adjustable Full-Scale Range

•

Adjustable Speed

–

Data Rate up to 6kSPS

–

Integration Times as low as 166.5ms

•

Daisy-Chainable Serial Interface

•

In-Package Bypass Capacitors Simplify PCB

Design

APPLICATIONS

•

CT Scanner DAS

•

Photodiode Sensors

•

X-Ray Detection Systems

DESCRIPTION

The DDC232 is a 20-bit, 32-channel, current-input

analog-to-digital (A/D) converter. It combines both

current-to-voltage and A/D conversion so that 32

separate low-level current output devices, such as

photodiodes, can be directly connected to its inputs

and digitized.

For each of the 32 inputs, the DDC232 provides a

dual-switched integrator front-end. This configuration

allows for continuous current integration: while one

integrator is being digitized by the onboard A/D

converter, the other is integrating the input current.

Adjustable integration times range from 166ms to 1s,

allowing currents from fAs to mAs to be continuously

measured with outstanding precision.

Protected by US Patent #5841310

The DDC232 has a serial interface designed for

daisy-chaining

in

multi-device

systems.

Simply

connect the output of one device to the input of the

next to create the chain. Common clocking feeds all

the devices in the chain so that the digital overhead

in a multi-DDC232 system is minimal.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2010, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.