100Ω
10kΩ
NOTE: (1) C
1
≈
C
OUT
2π R
f
f
c
G = 101
(40dB)
OPA604
Piezoelectric
Transducer
1MΩ
(1)
NOTE: (1) Provides input
bias current return path.
10
5
PCM63
20-bit
6
D/A
Converter 9
R
F
= Internal feedback resistance = 1.5kΩ
f
C
= Crossover frequency = 8MHz
C
1(1)
OPA604
V
O
= ±3Vp
To low-pass
filter.
FIGURE 7. High Impedance Amplifier.
FIGURE 8. Digital Audio DAC I-V Amplifier.
OPA604
A
2
I
2
R
4
OPA604
A
1
V
IN
R
2
I
1
R
3
51Ω
I
L
= I
1
+ I
2
51Ω
V
OUT
R
1
V
OUT
= V
IN
(1+R
2
/R
1
)
Load
FIGURE 9. Using Two OPA604 Op Amps to Double the Output Current to a Load.
OPA604
SBOS019A
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11