OPA2690 Datasheet, PDF (17/30 Pages) Burr-Brown (TI) – Dual, Wideband, Voltage-Feedback OPERATIONAL AMPLIFIER with Disable

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50Ω
V_I
1/2
O P A26 90
R_F
402Ω
R_G
R_F
402Ω
R_O
V_DIFF =
1+
2R_F
R_G
V_I − (−V_I)
1/2
R_O
50Ω _{O P A2 6 9 0}
−V_I
Figure 8. High-Speed Differential Receiver
OPA2690
SBOS238D − JUNE 2002 − REVISED DECEMBER 2004
SINGLE-SUPPLY MFB DIFFERENTIAL
ACTIVE FILTER: 10MHz BUTTERWORTH
CONFIGURATION
The active filter circuit shown in Figure 9 can be easily
implemented using the OPA2690. In this configuration,
each amplifier of the OPA2690 operates as an integrator.
For this reason, this type of application is also called
infinite gain filter implementation. A Butterworth filter can
be implemented using the following component ratios:
f_O + ₂
1
pR
R₁ + R₂ + 0.65
R₃ + 0.375 R
C₁ + C
C₂ + 2 C
C ^{(cutoff frequency)}
R
R_1A
102Ω
V_IN
R_1B
102Ω
+12V
6kΩ
V_CM ^50Ω
1000pF
6kΩ
R_3A
60Ω
1 /2
OP A 2 6 90
C_1A
100pF
C₂
200pF
R_2A
102Ω
R_2B
102Ω
R_3B
60Ω
C_1B
100pF
V_OUT
V_CM
50Ω
1 /2
OP A 2 6 90
Figure 9. Single-Supply, MFB Active Filter, 10MHz LP Butterworth
17