+5V
0.1µF
0.1µF
VREF
1
8
V+
7
6
5
DCLOCK
DOUT
500Ω
+In
2
Serial
Interface
ADS7816
12-Bit A/D
OPA340
VIN
–In
CS/SHDN
3
3300pF
GND
4
VIN = 0V to 5V for
0V to 5V output.
NOTE: A/D Input = 0 to VREF
RC network filters high frequency noise.
FIGURE 5. OPA340 in Noninverting Configuration Driving ADS7816.
+5V
330pF
0.1µF
0.1µF
5kΩ
5kΩ
VIN
1
VREF
8
V+
7
6
5
DCLOCK
DOUT
+In
2
Serial
Interface
ADS7816
12-Bit A/D
OPA340
–In
CS/SHDN
3
GND
4
VIN = 0V to –5V for 0V to 5V output.
NOTE: A/D Input = 0 to VREF
FIGURE 6. OPA340 in Inverting Configuration Driving ADS7816.
Filters 160Hz to 2.4kHz
+5V
10MΩ
VIN
243kΩ
1.74MΩ
1/2
OPA2340
200pF
1/2
OPA2340
10MΩ
47pF
RL
220pF
FIGURE 7. Speech Bandpass Filter.
®
OPA340/2340/4340
10