Power Amplifier (La4598) - Casio CTK-450 Service Manual

Power Amplifier (LA4598)

LA4598 is a 2-channel power amplifier with stand-by switch.
The following table shows the pin functiion of the power amplifier.
Pin No. Terminal
1 Power GND
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
Block Diagram
6
Ch1 IN
5
Ch1 NF
Pre GND 8
7
D.C.
10
Ch2 IN
11
CH2 NF
In/Out
In Ground (0V) source
Terminal for bootstrap capacitor
Out Channel 1 output
In +9V source
In Negative feedback input
In Channel 1 input
Terminal for decoupling capacitor
In Ground (0V) source
In Power control signal input. 0V: OFF, +9V: ON
In Channel 2 input
In Negative feedback input
Out hannel 2 output
Terminal for bootstrap capacitor
Not used.
Input
Pre-drive
Amp.
Amp.
Bias circuit
Input
Pre-drive
Amp.
Amp.
— 7 —
Function
2
CH2 BS
Power
3
CH1 OUT
Amp.
1 POWER GND
4 VCC
TSD protector
9
STAND BY
Stand by
Power
CH2 OUT
12
Amp.
13 CH2 BS