— 6 —
FILTER BLOCK
Since the sound signals from the CPU is stepped waveforms, the filter block is added to smooth the waveforms.
POWER AMPLIFIER (IC101: LA4598)
The power amplifier is a two-channel amplifier with standby switch.
The following table shows the pin function of IC101.
Amp.
LA4598
Filter
Block
CPU
MSM6755C-17
Pin No.
Terminal
In/Out
Function
1
Power GND
In
Ground (0 V) source
2
Ch1 B.S.
—
Terminal for a bootstrap capacitor
3
Ch1 OUT
Out
Channel 1 output
4
VCC
In
+9 V source
5
Ch1 N.F.
In
Negative feedback input
6
Ch1 IN
In
Channel 1 output
7
D.C
—
Terminal for a bootstrap capacitor
8
Pre GND
In
Ground (0 V) source
9
Stand by
In
Power control signal input. 0 V:Off, +9 V: On
10
Ch2 IN
In
Not used. Connected to ground (0 V)
11
Ch2 N.F.
In
Negative feedback input
12
Ch2 OUT
Out
Channel 2 output
13
Ch2 B.S.
—
Terminal for a bootstrap capacitor
14
NC
—
Not used
Summary of Contents for CTK-411
Page 11: ...9 Top View PRINTED CIRCUIT BOARDS Main PCB JCM444 MA1M Bottom View 3 2 7 6 4 5 1...
Page 12: ...10 SCHEMATIC DIAGRAMS Main PCB JCM444 MA1M 1 5 4 2 3 7 6...
Page 13: ...11 Sub PCBs JCM444 MA2M MA3M...
Page 14: ...12 Keyboard PCBs JCM4911K KY1M KY2M...
Page 16: ...14 EXPLODED VIEW 18 6 14 13 15 R 1 5 8 7 9 10 11 12 1 2 19 4 17 16 4 R 3 R 5 3 R 4 R 2...
