Datasheet
ADS1212, 1213
32
SBAS064A
Four-Wire Interface
Figure 30 shows a four-wire interface with a 8xC32 micro-
processor. Again, the Slave Mode is being used.
Multi-Wire Interface
Figures 31 and 32 show multi-wire interfaces with a 8xC51
or 68HC11 microprocessor. In these interfaces, the mode of
the ADS1212/13 is actually controlled dynamically. This
could be extremely useful when the ADS1212/13 is to be
used in a wide variety of ways. For example, it might be
desirable to have the ADS1212/13 produce data at a steady
rate and to have the converter operating in the Continuous
Read Mode. But for system calibration, the Slave Mode
might be preferred because multiple instructions can be
issued per conversion period.
Note that the MODE input should not be changed in the
middle of a serial transfer. This could result in misoperation
of the device. A Master/Slave Mode change will not affect
the output data.
Note that the X
IN
input can also be controlled. It is possible
with some microcontrollers and digital signal processors to
produce a continuous serial clock, which could be connected
to the X
IN
input. The frequency of the clock is often settable
over some range. Thus, the power dissipation of the
ADS1212/13 could be dynamically varied by changing both
the Turbo Mode and X
IN
input, trading off conversion speed
and resolution for power consumption.
I/O Recovery
If serial communication stops during an instruction or data
transfer for longer than 4 • t
DATA
, the ADS1212/13 will reset
its serial interface. This will not affect the internal registers.
The main controller must not continue the transfer after this
event, but must restart the transfer from the beginning.
This feature is very useful if the main controller can be reset
at any point. After reset, simply wait 8 • t
DATA
before
starting serial communication.
FIGURE 31. Full Interface with a 8xC51 Microprocessor.
ADS1212
A
IN
P
A
IN
N
AGND
V
BIAS
CS
DSYNC
X
IN
X
OUT
DGND
REF
IN
REF
OUT
AV
DD
MODE
DRDY
SDOUT
SDIO
SCLK
DV
DD
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
V
CC
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
8xC51
C
2
6pF
C
1
6pF
XTAL
AGND
DGND
AV
DD
DV
DD
DGND
AGND
1.0µF
R
2
10kΩ
R
1
10kΩ
FIGURE 30. Four-Wire Interface with a 8xC32 Microprocessor.
DGND
ADS1212
A
IN
P
A
IN
N
AGND
V
BIAS
CS
DSYNC
X
IN
X
OUT
DGND
REF
IN
REF
OUT
AV
DD
MODE
DRDY
SDOUT
SDIO
SCLK
DV
DD
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RESET
RXD
TXD
INT0
INT1
WR
RD
X2
X1
V
SS
8xC32
C
2
27pF
C
1
27pF
DV
DD
AGND
DGND
AV
DD
DV
DD
D
CLK
Q
Q
D
CLK
Q
Q
1/2 74HC74 1/2 74HC74
XTAL
AGND
1.0µF
R
1
10kΩ