FILTER BLOCK
Since the sound signals from the CPU is stepped waveforms, the filter block is added to smooth the waveforms.
Amp.
LA4598
POWER AMPLIFIER (IC101: LA4598)
The power amplifier is a two-channel amplifier with standby switch.
The following table shows the pin function of IC101.
Pin No.
Terminal
1
Power
2
Ch1 B.S.
3
Ch1 OUT
4
VCC
5
Ch1 N.F.
6
Ch1 IN
7
D.C.
8
Pre GND
9
Stand by
10
Ch2 IN
11
Ch2 N.F.
12
Ch2 OUT
13
Ch2 B.S.
14
NC
Filter
Block
In/Out
GND
In Ground (0 V) source
—
Terminal for a bootstrap capacitor
Out
Channel 1 output
In
+9 V source
In
Negative feedback input
In
Channel 1 input
—
Terminal for a decoupling capacitor
In
Ground (0 V) source
In
Power control signal input. 0 V: Off, +9 V: On
In
Channel 2 input
In
Negative feedback input
Out
Channel 2 output
—
Terminal for a bootstrap capacitor
—
Not used
— 7 —
CPU
MSM6755B-17
Function