9
KX-T7730CA
4.2.4.
TONE Generation Circuit
Function:
This circuit generates all system tones including COL, extension, busy, DTMF signals and key in confirmation tones during the
power failure mode and is comprised of IC1(DTMF Generator) and IC5 (Analog Switch).
Circuit Operation:
For an output of a single row tone, the row terminal and the each column terminals intersecting with it are required to be brought
a low state. For a dual tone output, one row terminal and one column terminal are brought to low state.
CONDITION
IC1 pin52
IC5 SWA
IC1 pin53
IC5 SWB
IC1 pin54
IC5 SWC
IC1 pin55
IC5 SWD
Ringing
L
OFF
L
OFF
L
OFF
H
ON
Call Waiting
L
OFF
L
OFF
H
ON
L
OFF
Tone Dial (Handset)
H
ON
H
ON
L
OFF
L
OFF
Tone Dial (Speakerphone)
H
ON
L
OFF
H
ON
L
OFF
Summary of Contents for KX-T7730CA
Page 12: ...12 KX T7730CA ...
Page 13: ...13 KX T7730CA 5 Location of Controls and Components ...
Page 15: ...15 KX T7730CA 7 Troubleshooting Guide 7 1 No Operation ...
Page 16: ...16 KX T7730CA 7 2 Handset Trouble ...
Page 17: ...17 KX T7730CA 7 3 Speaker Phone Trouble 7 4 TONE Dial Trouble ...
Page 21: ...21 KX T7730CA 9 Miscellaneous 9 1 Terminal Guide of ICs Transistors and Diodes ...
Page 23: ...23 KX T7730CA 9 3 Memo ...
Page 30: ...30 KX T7730CA 13 2 Cabinet and Electrical Parts Location ...
Page 31: ...31 KX T7730CA 13 3 Accessories and Packing Materials ...