BA3430S Rohm Semiconductor, BA3430S Datasheet - Page 8

• Manufacturer Part Number: BA3430S
• Description: IC PREAMP AUDIO STER AB 24SDIP
• Manufacturer: Rohm Semiconductor
• Type: Class ABr

Specifications of BA3430S

• Output Type: 2-Channel (Stereo)
• Voltage - Supply: 7 V ~ 18 V
• Mounting Type: Through Hole
• Package / Case: 24-SDIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Max Output Power X Channels @ Load: -

(3) Sensitivity switch amplifier
Equivalent circuit schematic
(4) Comparator circuit
This circuit detects the presence or not of the signal and
outputs a detection signal.
The circuit consists of two comparators. The first
comparator detects the level of the signal and the second
comparator detects the duration of the signal.
When a signal above V
comparator turns on and draws a constant current I from
the time constant pin. This causes the voltage of the time
constant pin to fall, and when it drops below V
the next comparator turns on, changing the mute detec-
tion output pin to low.
If the signal level drops below V
comparator turns off and the voltage of the time constant
pin rises due to the external discharge resistor. When this
voltage rises above V
turns off, changing the mute detection output pin to high.
The time
of the mute detection output pin to low is given as follows:
276
Audio ICs
1
=
1
from the arrival of the signal to the changeover
5.4 C
I
(S)
CC
CC
- 2.0(V), the next comparator
/ 30 (V
O-P
CC
/ 30 (V
) is input, the first
O-P
CC
), the first
- 2.7(V)
R2 is a resistor inside the IC which is 100 during play-
back and 360 during fast forward.
The gain of the amplifier is
The low cutoff frequency f
This equation holds when the input signal is sufficiently
large.
See Fig. 20 for the small signal time
The time
over of the mute detection output pin to high is as follows:
I: Output current of first comparator = approx. 1mA
C: External capacitor connected to time constant pin
R: External resistor connected to time constant pin (this
should be 22k or higher)
Equivalent circuit schematic
2
= C R In
G = 20
f
L
=
BA3430S / BA3430F / BA3430FS
2
2
from the ceasing of the signal to the change-
log
1/2 V
C
1
30k ) R1 ) R2
(R1 ) R2)
2.0
R1 ) R2
CC
L
)2.0
of the amplifier is
(S)
(Hz)
1
.
(dB)