RXD
22
TTL
input
PCM
interface
Input terminal for PCM data
TXD
23
Output
Output terminal for PCM data
-FSYNC
24
TTL
input
Input terminal of Sync. signal for PCM interface. The frequency
of input sync.
signal is 8 kHz.
BCLK
25
Input terminal of shift clock pulse for PCM deta. Input pulse
frequency renge is 64 kHz~2.048 kHz.
PCM data (TXD termianl signal) is output st the positive
PCM data (RXD terminal signal) is sampled at the negative
The sameling is performed inside LSI.
MCLK
26
Output
Clock
Clock pulse output terminal. Output pulse frequency is
6.144MHz.
System reset (inputting “0” to -RESET terminal) doesn’t
this output.
CLKO
27
Clock pulse output terminal which has selective frequencies.
The following 4 frequencies can be selected by resistor
12.228, 4.096, 2.048, 1.536 (MHz).
System reset (inputting “0” to -RESET terminal) selects
frequency of 1.536MHz and doesn’t stop this output.
DG2
28
---
Power
supply, etc.
Ground terminal of digital circuit.
OSCI
29
---
Clock
Input terminal of oscillation circuit.
Connect the oscillator and resistor berween this terminal
pin 30 (OSCO), moreover, connect the capacitor between
terminal and digital ground to make the oscillation circuit.
OSCO
30
---
Output terminal of oscillation circuit.
Connect the oscillator and resistor berween this terminal
pin 29 (OSCI), moreover, connect the capacitor between
terminal and digital ground to make the oscillation circuit.
D5V2
31
---
Power
supply, etc.
5V power supply terminal of digital circuit.
-INT
44
Output
Micro-
computer
interface
Outputs 8 kHz clock pulse which is synchronized with -
TEST
45
CMOS
input
Power
supply, etc.
Test terminal
Connect to the digital ground.
A5V3
46
---
5V power supply terminal of analog circuit.
HI
47
Analog
input
Analog
Input terminal of TX handset signal.
Either this signal or the signal supplied to pin 49 (HI) is
AD converter.
VBB
48
---
Power
supply, etc.
Reference voltage terminal of AD converter.
Connect the capacitor of 10
F between VBB termunal
50 (AG3).
13
Summary of Contents for KX-T7456 - Digital 24 Button Speakerphone Display
Page 4: ...4 DISASSEMBLY INSTRUCTIONS 4 1 HOW TO REMOVE THE LOWER CABINET Procedure 1 4 ...
Page 8: ...5 IC DATA 5 1 IC1 8 ...
Page 11: ...11 ...
Page 15: ...15 ...
Page 20: ...7 4 DATA COMMUNICATION CIRCUIT 1 Function 20 ...
Page 24: ...The reset signal is negledted 24 ...
Page 29: ...8 TROUBLESHOOTING GUIDE 8 1 NO OPERATION 8 2 THE LCD DOES NOT OPERATE 29 ...
Page 31: ...8 5 SPEAKER PHONE TROUBLE 8 6 TONE DIAL TROUBLE 8 7 TROUBLE OF OHCA 31 ...
Page 32: ...8 8 HANDSET TROUBLE 9 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 32 ...
Page 36: ...12 CABINET AND ELECTRICAL PARTS LOCATION 13 ACCESSORIES AND PACKING MATERIALS 36 ...
Page 49: ...33 37 34 35 36 25 32 ...
Page 55: ...SW301 CN301 1 2 3 ...
Page 57: ...1 5 2 6 3 7 4 8 ...
Page 58: ...9 13 10 14 11 15 12 16 ...
Page 59: ...17 21 18 22 19 23 20 24 ...