OPA365-Q1_16 Datasheet, PDF (19/22 Pages) Texas Instruments – Single-Supply Operational Amplifiers

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OPA365-Q1, OPA2365-Q1
SBOS512D – MARCH 2010 – REVISED DECEMBER 2015
Typical Application (continued)
9.2.2.1 Design Requirements
Use the following design parameters for this application:
• Supply voltage: 2.2 V to 5 V
• Input signal: 0 V to 25 mV
• Input signal frequency: 0 MHz to 1 MHz
9.2.2.2 Detailed Design Procedure
Some applications need bandpass filter–that is, radar or audio signal precessing. The cross over frequencies and
flat gain can be adjusted by changing the resistors and capacitors value according to applications.
The circuit is designed for 5-V supply and 20-mV input signal. With a flat gain of 100 dB or 40 dB, the peak
output signal is 2 V. The reference signal is at half way of 5 V, which is 2.5 V.
The transfer
function or
gain =
V_out
V_in
=
-
(1
+
R₂C₁S
R₁C₁S) (1+
R₂C₂S)
(1)
1
A zero at =
= 14.2 Hz
2p R₂C₁
(2)
A pole at = ¹ = 1.54 KHz
2p R₁C₁
(3)
A pole at = ¹ = 156 KHz
2p R₂C₂
(4)
Flat Gain of 100 or 40 dB between 1.54 kHz and 156 kHz
(5)
20 db/decade below 1.54 KHz
(6)
–20 dB/decade above 156 kHz
(7)
Bandpass between 1.54 kHz and 156 kHz
(8)
9.2.2.3 Application Curves
Figure 34. Gain Is –3 dB Below the Flat Gain at 1.5 kHz
Figure 35. Gain Is –3 dB Above the Flat Gain at 160 kHz
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Product Folder Links: OPA365-Q1 OPA2365-Q1