DDC264

Serial

Interface

DVALID

DCLK

DOUT

DIN

Configuration

and

Control

IN2

IN1

DGND

AGND

IN4

IN3

IN62

IN61

DS

ADC

IN64

IN63

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

0.2 F

m

0.1 F

m

0.3 F

m

DS

ADC

DS

ADC

DS

ADC

DDC264

www.ti.com

SBAS368C

– MAY 2006 – REVISED JULY 2011

64-Channel, Current-Input

Analog-to-Digital Converter

Check for Samples: DDC264

The DDC264 has a serial interface designed for

1

FEATURES

daisy-chaining

in

multi-device

systems.

Simply

2

•

Single-Chip Solution to Directly Measure 64

connect the output of one device to the input of the

Low-Level Currents

next to create the chain. Common clocking feeds all

•

Proven High-Precision, True Integrating

the devices in the chain so that the digital overhead

Architecture with 100% Charge Collection

in a multi-DDC264 system is minimal.

•

Easy Upgrade for Existing DDC Family

The DDC264 uses a +5V analog supply and a +2.7V

Applications

to +3.6V digital supply. Bypass capacitors within the

•

Very Low Power: 3mW/channel

DDC264

package

help

minimize

the

external

•

Extremely Linear:

component

requirements.

Operating

over

the

INL =

±0.025% of Reading ±1.0ppm of FSR

temperature range of 0

°C to +70°C, the DDC264

BGA-100 package is offered in two versions: the

•

Low Noise: 6.3ppm of FSR

DDC264C

for

low-power

applications,

and

the

•

Adjustable Full-Scale Range

DDC264CK when higher speeds are required.

•

Adjustable Speed

– Data Rates up to 6kSPS with 20-bit

Performance

– Integration Times as low as 160μs

•

Daisy-Chainable Serial Interface

•

In-Package Bypass Capacitors Simplify PCB

Design

APPLICATIONS

•

CT Scanner DAS

•

Photodiode Sensors

•

X-Ray Detection Systems

DESCRIPTION

The DDC264 is a 20-bit, 64-channel, current-input

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

current-to-voltage and A/D conversion so that 64

separate low-level current output devices, such as

photodiodes, can be directly connected to its inputs

and digitized.

For each of the 64 inputs, the DDC264 uses the

proven

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. This architecture provides both a

very stable offset and a loss-less collection of the

input current. Adjustable integration times range from

160

μs to 1s, allowing currents from fAs to μAs to be

continuously measured with outstanding precision.

Protected by US Patent #5841310

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

© 2006–2011, 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.