DDC232_15 Datasheet, PDF (1/34 Pages) Texas Instruments – 32-Channel, Current-Input Analog-to-Digital Converter

DDC232
www.ti.com
32-Channel, Current-Input
Analog-to-Digital Converter
Check for Samples: DDC232
SBAS331D – AUGUST 2004 – REVISED APRIL 2010
FEATURES
1
•2 Single-Chip Solution to Directly Measure 32
Low-Level Currents
• High-Precision, True Integrating Function
• 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
The DDC232 uses a +5V analog supply and a +2.7V
to +3.6V digital supply. Operating over the
temperature range of 0°C to +70°C, the DDC232
BGA-64 package is offered in two versions: the
DDC232C for low-power applications, and the
DDC232CK when higher speeds are required.
AVDD VREF
DVDD
0.1mF
0.1mF
0.1mF
IN1
Dual
Switched
Integrator
IN2
Dual
Switched
Integrator
IN3
Dual
Switched
Integrator
IN4
Dual
Switched
Integrator
DS
ADC
DS
ADC
Configuration
and
Control
CLK
CONV
DIN_CFG
CLK_CFG
RESET
DVALID
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.
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.
IN29
Dual
Switched
Integrator
IN30
Dual
Switched
Integrator
DS
ADC
Serial
Interface
DCLK
DOUT
IN31
Dual
Switched
Integrator
IN32
Dual
Switched
Integrator
DS
ADC
AGND
DGND
Protected by US Patent #5841310
DIN
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.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004–2010, Texas Instruments Incorporated