SM6802A

NIPPON PRECISION CIRCUITS INC.—9

Input Equalizer (LIN, LEQP, LEQN, RIN, REQP, REQN)

An input equalizer network can be connected to pins LIN, LEQP and LEQN (RIN, REQP and REQN), as

shown in the input equivalent circuit and equalizer circuit below.

The frequency response of the equalizer circuit is given by the following equation, where

ƒ is the frequency.

Dynamic Range Compression Mode (DRCN)

The dynamic range compression mode is set when DRCN is LOW. When a compression mode is used, the gain

for small input signals is increased while large input signals are converted using a curve that performs soft-clip-

ping. This increases the average sound pressure level emitted from the speaker during playback.

LEQN

(REQN)

VREF1

LEQP

(REQP)

R04

R03 C03

C04

R01

60k

R02 C02

60k

LIN

(RIN)

2

C01

IN'

+

−

1

20

Response =

20 × log

10

[dB]

11

60000

1

R04

++

+ 2πƒC04

1

2

πƒC03

R03

+

+

1

2

πƒC01

1

1

60000

1

R01

+

1

+

1

2

πƒC02

R02

+

1

-20

-15

-10

-5

0

5

10

-40

-35

-30

-25 -20

-15

-10

-5

0

5

10

-40

-35

-30

-25

Input [dBV]

normal mode

DRC mode