CXA2561Q
4. Music sensor
TAPEIN2
D1
D2
DVcc
× 1
R10
Vcc
R3
127k
R2
10k
× 5
Full-
wave
rectifier
R4
100k
MSOUT
Smoother
AMP3
AMP1
R1
AMP2
10k
R5A
C1
64p
0.775V for
29k
R6
1k
signal detection
0.616V for no
signal detection
Q1
R5B
10k
VGS
× 1
G1FB
G2FB
MSTC
R9
TAPEIN1
MSLPF
C2
C3
C4
C5
R7
R8
Fig. 5. Music sensor block diagram
(1) Adjustment of music signal detection level
Adjustment the exrernal resistors R7 and R8 to adjust the music signal interval detection level.
The signal detection level v1 and no signal detection level v2 are expressed by the following equations.
v1 = –39 + 20log (39k/Rext) [dBm] Rext: R7 or R8
v2 = v1 – 2 [dBm]
(2) Low-frequency cut-off adjustment of music sensor
Adjust the external resistors R7, R8 and the external capacitors C3, C4 to adjust the low-frequency cut-off.
The low-frequency cut-off is expressed by the following equation.
fc1 = 1/ (2π · Cext · Rext) Cex, Rext: C3, R7 or C4, R8
(3) High-frequency cut-off adjustment of music sensor
Adjust the capacitor C2 to MSLPF (Pin 10) to adjust the high-frequency cut-off. The high-frequency
cut-off is expressed by the following equation.
fc2 = 1/ (2π · (64p + C2) · 100k)
The high-frequency cut-off is approximately 25kHz when MSLPF is left open.
(4) Response time adjustment
Adjust the external resistor R9 and the external capacitor C5 to adjust the response time.
The response time for signal detection depends on the internal resister R6 and the external capacitor C5.
The response time for no signal detection depends on the external resistor R9 and the external capacitor C5.
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SONY [ SONY CORPORATION ]
