PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
PE0
PE1
PE2
XIRQ
RESET
PC7
AVDD
AIN
P
N
PC6
REFIN
REFOUT
AVDD
1.0µF
AGND
AIN
PC5
68HC11
AGND
VBIAS
CS
PC4
PC3
PC2
PC1
PC0
XTAL
MODE
DRDY
SDOUT
SDIO
AGND
R1
10kΩ
ADS1212
DSYNC
XIN
C1
6pF
XOUT
DGND
SCLK
XTAL
R2
10kΩ
DVDD
DVDD
C2
DGND
6pF
FIGURE 32. Full Interface with a 68HC11 Microprocessor.
VDD2
DRDY
DGND
AVDD
VDD1
1.0µF
A
INP
REFIN
REFOUT
AVDD
SDOUT
AIN
N
AGND
VDD1
VDD2
DGND
GND
VDD2
AGND
VBIAS
CS
MODE
DRDY
SDOUT
SDIO
VDD1
AGND
VDD1
GND
ADS1212
SDIN
C1
R1
100Ω
DSYNC
XIN
6pF
DGND
XTAL
XOUT
SCLK
C2
6pF
DGND
DVDD
DGND
DGND
VDD1
SCLK
VDD2
DGND
GND
FIGURE 33. Isolated Four-Wire Interface.
In addition, the digital outputs of the ADS1212/13 can, in
some cases, drive opto-isolators directly. Figures 34 and 35
show the voltage of the SDOUT pin versus source or sink
current under worst case conditions. Worst-case conditions
for source current occur when the analog input differential
Isolation
The serial interface of the ADS1212/13 provides for simple
isolation methods. An example of an isolated four-wire
interface is shown in Figure 33. The ISO150 is used to
transmit the digital signals over the isolation barrier.
®
33
ADS1212, 1213
BB [ BURR-BROWN CORPORATION ]
