DDC232 Datasheet, PDF (7/28 Pages) Burr-Brown (TI) – 32-Channel, Current-Input Analog-to-Digital Converter

DDC232
www.ti.com
SBAS331C – AUGUST 2004 – REVISED SEPTEMBER 2006
THEORY OF OPERATION
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
Dual
IN1
Switched
Integrator
Dual
IN2
Switched
Integrator
Dual
IN3
Switched
Integrator
Dual
IN4
Switched
Integrator
VREF
DVDD
∆Σ
Modulator
Digital
Filter
CLK
Configuration
and
Control
CONV
DIN_CFG
CLK_CFG
RESET
∆Σ
Modulator
Digital
Filter
DVALID
IN29
Dual
Switched
Integrator
IN30
Dual
Switched
Integrator
IN31
Dual
Switched
Integrator
IN32
Dual
Switched
Integrator
∆Σ
Modulator
Digital
Filter
Serial
Interface
DCLK
DOUT
DIN
∆Σ
Modulator
Digital
Filter
AGND
DGND
Figure 2. DDC232 Block Diagram
Submit Documentation Feedback
7