.

5

7

G

R

R

Gain

0 2x

R

Frequency (Hz)

-60

-40

-20

0

20

100

1k

10k

100k

1M

4

1

C

3

4

2

5

R

Gain

R

1

f

1 R R C C

2

S

21

OPA4188

www.ti.com

SBOS641D – JUNE 2012 – REVISED SEPTEMBER 2016

Product Folder Links: OPA4188

Submit Documentation Feedback

Copyright © 2012–2016, Texas Instruments Incorporated

Typical Applications (continued)

This circuit produces a signal inversion. For this circuit, use Equation 2 to calculate the gain at DC and the low-

pass cutoff frequency.

(2)

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

and easy-to-use active filter design program. The WEBENCH Filter Designer lets you create optimized filter

designs 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, WEBENCH® Filter Designer allows you to

design, optimize, and simulate complete multi-stage active filter solutions within minutes.

9.2.1.3 Application Curve

Figure 45. Gain (dB) vs Frequency (Hz)

9.2.2 Discrete INA + Attenuation for ADC With a 3.3-V Supply

Figure 46 illustrates a circuit with high input impedance that can accommodate ±2 V differential input signals. The

output, VOUT, is scaled into the full scale input range of a 3.3 V analog to digital converter. Input common mode

voltages as high as ±10 V can be present with no signal clipping. Input stage gain is determined by resistors R5,

RG and R7 according to Equation 3 .

(3)