SM6802A Datasheet, PDF (9/15 Pages) Nippon Precision Circuits Inc – Class-D Stereo Amplifier for Portable Device

SM6802A
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.
C01
IN'
R01
R04
R02 C02
R03 C03
C04
LEQP 1
(REQP)
LEQN 20
(REQN)
60k
60k
2
−
LIN
+
(RIN)
VREF1
The frequency response of the equalizer circuit is given by the following equation, where ƒ is the frequency.
1
1₊
1
+ ¹ + 2πƒC04
60000 _{R03 +} 1
R04
2πƒC03
Response = 20 × log₁₀
[dB]
1₊
1
2πƒC01
1 ₊1₊
1
60000 R01 _{R02 +} 1
2πƒC02
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.
-40 -35 -30 -25 -20 -15 -10 -5 0 5 10
10
5
DRC mode
0
-5
-10
-15
-20
normal mode
-25
-30
-35
-40
Input [dBV]
NIPPON PRECISION CIRCUITS INC.—9