HA12215 Hitachi Semiconductor, HA12215 Datasheet - Page 12

• Manufacturer Part Number: HA12215
• Description: Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)
• Manufacturer: Hitachi Semiconductor

HA12215F
The Sensitivity of Music Sensor
Notes: 1. When there is not a regulation outside.
Time constant of detection
Notes 2. Attack
Like the figure 6(2), Recovery time is variably possible by value of resistor R13. But Attack time gets
about fixed value. Attack time has dependence by input level. When a large signal is inputted, Attack time
is short tendency.
Rev.5, Oct. 1999, page 12 of 69
A standard level of MS input pin 25.9 mVrms, therefore, the sensitivity of music sensor (S) can request
it, by lower formulas.
But necessary to consider the same attenuation quantity practically, on account of A(B) have made
frequency response.
Occasion of the external component of figure 4, f1 is 3.18 kHz.
Figure 6(1) generally shows that detection time is in proportion to value of capacitor C13. But, with
Attack*
2. Case of one-sided channel input.
3. Recovery : Music to Non-music
A = MS Amp Gain*
B = PB input Gain
C = Sensed voltage
20log (A
C = 130 [mVrms] (Intenally voltage in a standard)
PB input Gain = 21.3 [dB]
2
and Recovery*
Recovery
37.7dB
B) = D [dB]
C13
: Non- music to Music
(1)
G
V
Attack
1
3
the detection time differs exceptionally.
(1/2)*
Figure 5 Frequency Characteristic of MSIN
Figure 6 Function Characteristic of MS
2
f1
S = 20log
S = 14
Recovery
f2
D [dB]
25.9 A B
R13
(2)
Attack
C
f
Detection level
[dB]
f1 =
f2 = 25k [Hz]
2
C16 50k
1
Recovery
Input level
(3)
[Hz]
Attack