DDC232 Datasheet, PDF (1/28 Pages) Burr-Brown (TI) – 32-Channel, Current-Input Analog-to-Digital Converter

BurrĆBrown Products
from Texas Instruments
DDC232
SBAS331C – AUGUST 2004 – REVISED SEPTEMBER 2006
32-Channel, Current-Input
Analog-to-Digital Converter
FEATURES
• 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 DATA RATE: Up to 6kSPS
– Integration Times Down to 166.5µs
• DAISY-CHAINABLE SERIAL INTERFACE
APPLICATIONS
• CT SCANNER DAS
• PHOTODIODE SENSORS
• X-RAY DETECTION SYSTEMS
Protected by US Patent #5841310
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 166µs to 1s,
allowing currents from fAs to µAs 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.
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 is
offered in a BGA-64 package.
IN1
Dual
Swit ched
Integrator
IN2
Dual
Swit ched
Integrator
IN3
Dual
Swit ched
Integrator
IN4
Dual
Swit ched
Integrator
AVDD
VREF
DVDD
∆Σ
Modulator
Digital
Filter
Configuration
and
Control
CLK
CONV
DIN_CFG
CLK_CFG
RESET
∆Σ
Modulator
Digital
Filter
DVALID
IN29
Dual
Swit ched
Integrator
IN30
Dual
Swit ched
Integrator
IN31
Dual
Swit ched
Integrator
IN32
Dual
Swit ched
Integrator
∆Σ
Modulator
Digital
Filter
Serial
Interface
DCLK
DOUT
∆Σ
Digital
DIN
Modulator _Filter
AGND
DGND
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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 © 2004–2006, Texas Instruments Incorporated