鈥?/div>
SINGLE-CHIP SOLUTION TO DIRECTLY
MEASURE 32 LOW-LEVEL CURRENTS
HIGH-PRECISION, TRUE INTEGRATING
FUNCTION
INTEGRAL LINEARITY:
鹵0.025% of Reading 鹵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
鈥?Integration Times Down to 166.5碌s
DAISY-CHAINABLE SERIAL INTERFACE
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擄C to +70擄C, the DDC232 is
offered in a BGA-64 package.
AVDD
VREF
DVDD
IN1
Dual
Switched
Integrator
CLK
鈭單?/div>
Modulator
CONV
Digital
Filter
Configuration
and
Control
DIN_CFG
CLK_CFG
RESET
APPLICATIONS
CT SCANNER DAS
PHOTODIODE SENSORS
X-RAY DETECTION SYSTEMS
Protected by US Patent #5841310
IN2
Dual
Switched
Integrator
IN3
Dual
Switched
Integrator
鈭單?/div>
Modulator
IN4
Dual
Switched
Integrator
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 166碌s to 1s,
allowing currents from fAs to
碌A(chǔ)s
to be continuously
measured with outstanding precision.
Digital
Filter
DVALID
IN29
Dual
Switched
Integrator
DCLK
鈭單?/div>
Modulator
Serial
Interface
Digital
Filter
IN30
Dual
Switched
Integrator
DOUT
IN31
Dual
Switched
Integrator
鈭單?/div>
Modulator
IN32
Dual
Switched
Integrator
Digital
Filter
DIN
AGND
DGND
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.
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 漏 2004鈥?006, Texas Instruments Incorporated
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