Casio casio electronic keyboard manual Filter Block, Power Amplifier IC101 LA4598, Cpu, Vcc

Page 8

FILTER BLOCK

Since the sound signals from the CPU is stepped waveforms, the filter block is added to smooth the waveforms.

Amp.

LA4598

Filter Block

CPU

MSM6755C-17

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

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

 

 

 

 

— 6 —

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Contents CTK-431 Contents Electrical SpecificationsGeneral Block Diagram Circuit Description KEY Matrix Nomenclature of Keys CasioNCO MrdbMcsb DgndLCD Driver LSI3 KS0066U-10B Power Amplifier IC101 LA4598 Filter BlockCPU VCCVR1 TP1 AdjustmentMain PCB Major Waveforms Printed Circuit Boards Schematic Diagrams Sub PCBs JCM444-MA2M/MA3M Keyboard PCBs JCM4911K-KY1M/KY2M LCD SegmentExploded View Parts List Keyboard PCBs Overseas Service Division