Amplitude Equalization

Sending signals over coaxial cable greater than 50

meters in length will attenuate high frequency signal

components. Equalizers restore the attenuated com-

ponents of this signal. The circuit in Figure 4, is an op

amp equalizer. The RC networks peak the response of

the CLC405 at higher frequencies.

This peaking

restores cable-attenuated frequencies. Graph 2 shows

how the equalizer actually restored a digital word

through 150 meters of coaxial cable.

Figure 4

Graph 2

Amplitude Equalizer

khz for Graph 2).

Graph 3 shows the closed loop response of the op

amp equalizer with equations for the poles, zeros,

and gains.

Graph 3

Note: For very-high frequency equalization, use a higher

bandwidth part (i.e. CLC44X)

Ordering Information

Model

Temperature Range

Description

CLC405AJP

8-pin PDIP

CLC405AJE

8-pin SOIC

CLC405AIB

8-pin CerDIP

CLC405ALC

dice

CLC405AMC

dice, MIL-STD-883

CLC405A8B

8-pin CerDIP, MIL-STD-883

Contact factory for other packages and DESC SMD number.

Package Thermal Resistance

Package

θθjc

θθjA

Plastic (AJP)

Surface Mount (AJE)

CerDip

Ω

+

-

CLC405

Input

Output

RC Networks

Coaxial Cable

Digital Word Amplitude Equalization

Time (200ns/div)

Unequalized

Equalized

Closed Loop Equalizer Frequency Response

Frequency (Hz)

fz

1

2R C

R C

1

11

g

1

=

+

()

π

fp

1

2R C

1

11

=

π

fz

1

2R C

R C

2

22

eq

2

=

+

()

π

fp

1

2R C

2

22

=

π

R

R llR

eq

1

g

=

G

20log (1

R

2R

)

1

g

1

=+

G

20log (1

R

2R

)

2

eq

2

=+

The values used to produce Graph 2 are:

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sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can

be reasonably expected to result in a significant injury to the user.

2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to

cause the failure of the life support device or system, or to affect its safety or effectiveness.

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