DSP56004
ADS7816
WST
VREF
CS
DOUT
SDO0
SDO1
SDO2
SCKT
SCKR
SDI0
+
+
+
10µF
10µF
10µF
0.1µF
0.1µF
0.1µF
+In
–In
DCLOCK
Serial Audio
Interface
ADS7816
VREF
+In
CS
DOUT
SDI1
–In
DCLOCK
WSR
ADS7816
SCK/SCL
MISO/SDA
MOSI/HA0
HREQ
VREF
+In
CS
DOUT
Serial Host
Interface
–In
DCLOCK
SS/HA2
10Ω
10Ω
10Ω
DAC56
VOUT
LE
CLK
DATA
FIGURE 7. Flexible Data Acquisition System.
+5V
5Ω to 10Ω
+
1µF to
10µF
ADS7816
VREF
VCC
1µF to
+
0.1µF
10µF
Microcontroller
+In
CS
DOUT
–In
GND
DCLOCK
FIGURE 8. Basic Data Acquisition System.
The ADS7816s and the DSP56004 can all be placed into a
power down mode. Or, the DSP56004 can run the ADS7816s
at a full 3.2MHz clock rate while on-board software enables
the ADS7816s as needed. With additional glue logic, the
DSP56004 could be used to run multiple DAC56s or provide
CS controls for each of the three ADS7816s.
Figure 8 shows a basic data acquisition system. The ADS7816
input range is 0V to 5V, as the reference input is connected
directly to the +5V supply. The 5Ω to 10Ω resistor and 1µF
to 10µF capacitor filter the microcontroller “noise” on the
supply, as well as any high-frequency noise from the supply
itself. The exact values should be picked such that the filter
provides adequate rejection of the noise.
®
13
ADS7816
BB [ BURR-BROWN CORPORATION ]
