Recom-

Effect

PN

mended

Purpose

Smaller

Larger

Remarks

Value

C1

10 mF

Power supply

Poor supply

Better supply

Do not use less

decoupling

rejection

rejection

than 10 mF

C2C11

1 mF

Input coupling

Increases

Reduces

DC voltage at pin 2

capacitor

frequency of low-

frequency of low-

and pin 13 is 035V

frequency roll-off

frequency roll-off

f

1

C3C10

22 nF for Stereo

Establishment of Min

Bandwidth

Bandwidth

See Note 4

15 nF for mono

and Max Bandwidth

becomes wider

becomes narrower

C4C8

1 mF

Output coupling

Increases

Reduces

DC voltage at pin 4

capacitor

frequency of low-

frequency of low-

and pin 11 is 035V

frequency roll-off

frequency roll-off

f

1

Works with R1 and R2

Some high frequency

Bandwidth may

to set one of the low-

program material

increase due

C5

01 mF

frequency corners

may be attenuated

to low-frequency

f

1

16 kHz

in control path

inputs causing

‘‘Breathing’’

See Note 4

Works with input

resistance of pin 6

C6

820 pF

to set one of the

Same as

Same as

f

1

48 kHz

low-frequency

above

above

corners in the

See Note 4

control path

Works with input

resistance of pin 9

Same as

Same as

C7

39 nF

to form part of

above

above

f

1

48 kHz

control path

frequency weighing

See Note 4

C9

1 mF

Sets attack time

Reduces attack

Increases attack

See Note 4

and decay time

and decay time

This voltage

Sensitivity should be set for

R1R2

divider sets

maximum noise reduction

control path

and minimum audible

sensitivity

frequency program effect

on high

R3

Sets gain amp load

Loads gain amp

Max bandwidth

when DNR is OFF

output may

will be reduced

cause distortion

Note 4

The values of the control path filter components (C5 C6 C7 C9 R1 R2) and the integrating capacitors (C3 C10) should not be changed from the

recommended values unless the characteristics of the noise or program material differ substantially from that of FM or tape sources Failure to use the correct

values may result in degraded performance and therefore the application may not be approved for DNR trademark usage Please contact National Semiconductor

for more information and technical assistance

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