Panasonic KX-TD7895 - Digital Spread Spedtrum Telephone, Service Manual, Page: 25 / 78

Bell signal, IC107(57) repeats High/Low fluctuation and then D105 in use is flashed. The data
signal indicating the Bell incoming is sent to the portable unit through the RF unit so the
handset ringer is on.
7.1.3. LINE INTERFASE
The line is looped when the IC107(46) becomes High and Q107 and Q100 are ON. The looped
current flows through Q100 Q108 R180. The pulse signal is generated when the IC105(41)
is repeatedly turned ON/OFF.
7.1.4. RECEIVED VOICE SIGNAL PATH
The analog input signal from the telephone line is changed to a digital signal and sent to the RF
unit via the following path:
T/R D101 Q100 R185 C184 R217 C186 Q104 R105 C104 C125
R128 IC102(3) IC102(4) C131 C147 R194 IC106(1) IC106(25) RF unit
7.1.5. SENT VOICE SIGNAL PATH
The digital input signal from the RF unit is changed to an analog signal by IC106 and sent to the