DDC232_15 Datasheet, PDF (7/34 Pages) Texas Instruments – 32-Channel, Current-Input Analog-to-Digital Converter

DDC232
www.ti.com
SBAS331D – AUGUST 2004 – REVISED APRIL 2010
THEORY OF OPERATION
GENERAL DESCRIPTION
The block diagram of the DDC232 is shown in
Figure 2. The device contains 32 identical input
channels that perform the function of
current-to-voltage integration followed by a
multiplexed A/D conversion. Each input has two
integrators so that the current-to-voltage integration
can be continuous in time. The output of the 64
integrators are switched to 16 delta-sigma (∆Σ)
converters via multiplexers. With the DDC232 in the
continuous integration mode, the output of the
integrators from one side of the inputs will be digitized
while the other 32 integrators are in the integration
mode. This integration and A/D conversion process is
controlled by the system clock, CLK. The results from
side A and side B of each signal input are stored in a
serial output shift register. The DVALID output goes
low when the shift register contains valid data.
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
IN29
Dual
Switched
Integrator
IN30
Dual
Switched
Integrator
DS
ADC
Serial
Interface
DCLK
DOUT
IN31
Dual
Switched
Integrator
IN32
Dual
Switched
Integrator
DS
ADC
DIN
AGND
DGND
Figure 2. DDC232 Block Diagram
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Product Folder Link(s): DDC232
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