Casio CTK-541 User Manual

CTK-541

INDEX

JULY.1999

E E E

CTK-541

ELECTRONIC KEYBOARD

CONTENTS

Specifications ................................................................................................................................... 1

Block Diagram.................................................................................................................................. 3

Circuit Description ............................................................................................................................ 4

Adjustment ....................................................................................................................................... 8

Major Waveforms ........................................................................................................................... 10

Printed Circuit Boards .................................................................................................................... 11

Schematic Diagrams ...................................................................................................................... 15

Exploded View ............................................................................................................................... 19

Parts List ........................................................................................................................................ 20

SPECIFICATIONS

GENERAL

Keyboard: 61 standard-size keys, 5 octaves (with touch response on/off) Tones: 100 Polyphony: 16 notes maximum (8 for certain tones) Auto accompaniment

Rhythm patterns: 100 Tempo: Variable (236 steps, = 20 to 255) Chords: 2 fingering methods (CASIO CHORD, FINGERED) Rhythm controller: START/STOP, SYNCHRO/FILL-IN Accomp volume: 0 to 9 (10 steps)

Song bank

Tunes: 100 Controllers: PLAY/PAUSE, STOP, REW, FF, LEFT ON/OFF (ACCOMP), RIGHT ON/

OFF (MELODY)

Display

Name display: TONE, RHYTHM, SONG BANK name/number, keyboard settings name/value Tempo: Tempo value, metronome, synchro standby, beat indicator Chord: Chord name, Chord form Fingering: Fingering indicators, parts, pedal Song bank status: PLAY, PAUSE, REW, FF Staff: 5 octaves with sharp and flat indications

Keyboard: 5 octaves MIDI: 5 multi-timbre receive Other functions

Transpose: 12 steps (–6 semitones to +5 semitones)

Tuning: Variable (A4 = approximately 440 Hz ± 50 cents)

Volume: 0 to 9 (10 steps) Terminals

MIDI terminals: IN, OUT

Sustain terminal: Standard jack

Phones/Output terminal: Stereo standard jack

Output Impedance: 50 Ω Output Voltage: 3.5 V (RMS) MAX

Power supply terminal: 9 V DC Power supply DC 9 V

Batteries: 6 D-size batteries

Battery life: Approximately 5 hours on manganese batteries

Auto power off: Turns power off approximately six minutes after last key operation. Enabled

under battery power only, can be disabled manually. Speaker output: 2.0 W + 2.0 W Power consumption: 9 V --- 7.7 W Dimensions (HWD): 961 × 376 × 143 mm (37-7/8 × 14-13/16 × 5-5/8 inches)

Weight: Approximately 5.7 kg (12.6 lbs) (without batteries)

— 1 —

ELECTRICAL

Current drain with 9 V DC: Nominal Limit

No sound output 330 mA 330 mA ± 20% Maximum volume 990 mA 990 mA ± 20%

with 16 keys C1 to D3 pressed in Synth-Lead 1 Volume: Maximum, Touch response: ON(Velocity MAX)

Phone output level (Vrms with 8 Ω load each channel): L 240mV 240 mV ± 20%

with key C3 pressed in Synth-Lead 1 R 250mV 250 mV ± 20%

Speaker output level (Vrms with 4 Ω load each channel):

with key G1 pressed in Synth-Lead 1 L/R 2500mV 2500 mV ± 20%

Output level (Vrms with 47 KΩ load each channel): L 2300mV 2300 mV ± 20%

with key C2 pressed in Synth-Lead 1 R 2400mV 2400 mV ± 20%

Minimum operating voltage: 6.3V 7.0V

— 2 —

— 3 —

CPU

GT913F(T)

LSI1

Keyboard

Buttons

LCD

LCD Driver

KS0066U-10B

LSI3

Reset IC

UPD6379GR-E1

IC1

Oscillator

X1, Q1

Power Supply Circuit

Q201 ~ Q203, Q207, Q208, D205

Power Amp.

TA8248K

IC201

Filter (L)

Q206

Filter (R)

Q205

Phone/Output

VC VCC DVDD

AVDD

APO

DC + 9V IN

DB4 ~ DB7

MIDI IN MIDI OUT

COM1 ~ COM16

SEG1 ~ SEG40

RS R/W E

KI0,KI1 FI8~FI10

FI0 ~ FI7

KC0 ~ KC7

MD0 ~ MD15

MA0 ~ MA19

ROM(8M-bit)

MSM538002E-

N8GS - KDR1

LSI2

Power Switch

BLOCK DIAGRAM

CIRCUIT DESCRIPTION

KEY MATRIX

KI0 KI1 KI2 KI3 KI4 KI5 KI6 KI7

KO0 C2 G#2 E3 C4 G#4 E5 C6 G#6

KO1 C#2 A2 F3 C#4 A4 F5 C#6 A6

KO2 D2 A#2 F#3 D4 A#4 F#5 D6 A#6

KO3 D#2 B2 G3 D#4 B4 G5 D#6 B6

KO4 E2 C3 G#3 E4 C5 G#5 E6 C7

KO5 F2 C#3 A3 F4 C#5 A5 F6

KO6 F#2 D3 A#3 F#4 D5 A#5 F#6

KO7 G2 D#3 B3 G4 D#5 B5 G6

KO8 —+0

KO9 321

KO10 6 5 4 Rhythm Tone

Tempo

Down

Start/

Stop

Transpose/

Tune/MIDI

KO11 9 8 7 Fingered Normal Off

KO12 FF Right Stop Left REW

Play/

Pause

Tempo

Synchro/

Fill-In

Song Bank

CASIO

Chord

Volume

Down

Chord

Book

Volume

Accomp

Volume

NOMENCLATURE OF KEYS

C#2

C2 D2E2F2G2A2 B2 C3 D3

F#2D#2

C#3A#2G#2

F#3 G#3

D#3

F3 G3 A3 B3 C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5

A#3 C#4 D#4

F#4 G#4

A#4

C#5

D#5

F#5 G#5

A#5

C#6

G#6F#6D#6

A#6

B6A6G6F6E6D6

— 4 —

CPU (LSI1: GT-913F)

The 16-bit CPU contains a 1k-byte RAM, three 8-bit I/O ports, two timers, a key controller and serial interfaces. The CPU detects key velocity by counting the time between first-key input signal FI and second-key SI from the keyboard. The CPU reads sound data and velocity data from the sound source ROM in accordance with the selected tone; the CPU can read rhythm data simultaneously when a rhythm pattern is selected. Then the CPU provides 16-bit serial sound data to the DSP. The CPU also controls MIDI input/output and stores sequencer data into the working storage RAM. The following table shows the pin functions of LSI1.

Pin No. Terminal In/Out Function

1 TXD0 Out MIDI signal output 2 RXD0 In MIDI signal input 3 SCK0 Out APO (Auto Power Off) signal output

4, 5

6 SCK1 Out 1 MHZ synchronizing pulse output 7 AVCC In CVDD (+5 V) source

8 AN0 In +5 V when the keyboard is powered by batteries and becomes 0 V

9 AN1 In Input from pitch bender 10 AGND In Ground (0 V) source 11 BCK Out Bit clock output 12 SO Out Serial sound data output 13 LRCK Out Word clock output 14 GND In Ground (0 V) source

15, 16 XLT0, XLT1 In/Out 30 MHz clock input/output

17 VCC In +5 V source

18, 19 MOD0, MOD1 In Mode selection terminal

20 RSTB In Reset signal input 21 NMI In Power ON signal input 22 INT/P10 In/Out Data bus for the LCD driver

TXD/P13,

RXD/P14

In/Out Data bus for the LCD driver

AC adaptor detection terminal.

to cancel the APO function when AC adaptor is connected.

23 ~ 30 31 ~ 38 KC0 ~ KC7 Out Terminal for key scan signal 39 ~ 50

51 FI10 In Terminal for button input signal 52 SI10/P23 Out Chip enable signal for the LCD driver

53 ~ 55 KI0 ~ KI2 In Terminal for button input signal

56 MWNB Out Write enable signal for the DSP

57 ~ 76 MA0 ~ MA19 Out Address bus

77 MCSB0 Out Chip enable signal output for the sound source ROM 78 MCSB1 Out Not used 79 MCSB2 Out Chip enable signal output for the DSP

FI0 ~ FI3

SI0 ~ SI3

FI4 ~ FI9

SI4 ~ SI9

In Terminal for key input signal

— 5 —

Pin No. Terminal In/Out Function

80 VCC In +5 V source 81 GND In Ground (0 V) source 82 MRDB Out Read enable signal output for the sound source ROM

83 ~ 98 MD0 ~ MD15 In/Out Data bus

99 PLE Out Reset signal output for the DSP

100 P17 In/Out Data bus for the LCD driver

LCD DRIVER (LSI3: KS0066U-10B)

The LCD driver can drive a dot matrix LCD having 40 segment and 16 common lines. The LSI contains 240 graphic symbols in the built-in character generator ROM, and stores 80 characters in the built-in display data RAM. In accordance with command from the CPU, the LSI is capable of displaying up to 16 characters simultaneously. The following table shows the pin functions of KS0066U-10B.

Pin No. Terminal In/Out Function

1 ~ 22,

63 ~ 80

23 VSS — GND (0 V) source

24, 25 OSC1, OSC2 In/Out

26 ~ 30 V1 ~ V5 In Those voltages are used for generating the stepped pulse of

31, 32 LP, XCLS — Not used

33 VDD In DVDD (+5 V) source

34, 35 FR, DO — Not used

36 RS In

37 R/W In Read/Write terminal. High: read, Low: write

38 E In High: enable, the writing is done at fall edge.

39 ~ 42 DB0 ~ DB3 — Not used. Connected to GND (0 V) 43 ~ 46 DB4 ~ DB7 In/Out Data bus 47 ~ 62 COM1 ~ COM16 Out Common signal/output

SEG1 ~ SEG40 Out Segment signal output

Terminals for the built-in clock pulse generator. The external resistor connected determines the oscillation frequency.

LCD drive voltage input.

the LCD drive signals.

Data/command determination terminal.

High: data, Low: command

Chip enable signal.

Low: disenable

— 6 —

+ 17 hidden pages