4

1

C

3

4

2

5

R

Gain

R

1

f

1 R R C C

2

S

1 3

2

5

2

2

1

3

4

3

4

2

5

1 R R C C

Output

s

Input

s

s C

1 R

1 R

1 R

1 R R C C

+

±

TLV376

Output

Input

R1

590

R4

2.94 k

R3

499

C2

39 nF

C5

1 nF

Copyright © 2016, Texas Instruments Incorporated

18

TLV376, TLV2376, TLV4376

SBOS755 – OCTOBER 2016

www.ti.com

Product Folder Links: TLV376 TLV2376 TLV4376

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Copyright © 2016, Texas Instruments Incorporated

8.2 Typical Application

Figure 29. Second-Order, Low-Pass Filter

8.2.1 Design Requirements

Low-pass filters are commonly employed in signal-processing applications to reduce noise and prevent aliasing.

The TLV376 is ideally suited to construct high-speed, high-precision active filters. Figure 29 shows a second-

order, low-pass filter commonly encountered in signal-processing applications.

Use the following parameters for this design example:

•

Gain = 5 V/V (inverting gain)

•

Low-pass cutoff frequency = 25 kHz

•

Second-order Chebyshev filter response with 3-dB gain peaking in the passband

8.2.2 Detailed Design Procedure

The infinite-gain multiple-feedback circuit for a low-pass network function is shown in the Application Curve

section. Use Equation 1 to calculate the voltage transfer function.

(1)

This circuit in Figure 29 produces a signal inversion. For this circuit, the gain at dc and the low-pass cutoff

frequency are calculated by Equation 2:

(2)

Software tools are readily available to simplify filter design. The WEBENCH® filter designer is a simple, powerful,

and easy-to-use active filter design program. The WEBENCH® filter designer allows optimized filter designs to

be created by using a selection of TI operational amplifiers and passive components from TI's vendor partners.

Available as a web-based tool from the WEBENCH® design center, the WEBENCH® filter designer allows

complete multistage active filter solutions to be designed, optimized, and simulated within minutes.