Circuit Operation (Rf Unit); Signal Route - Panasonic KX-TCA256X Service Manual

4.4.

Circuit Operation (RF Unit)

To measure the charge-current, R616-619 transfer the current to a voltage.
When the charge-current is 200mA, the voltage is 0.05V.
IC602 amplifies the voltage to 24.5time, then the output voltage is 24.5X0.05=1.225V.
IC601 is DC/DC convertor. This IC adjusts CII to 1.25V.
Then the charge current is adjusted to 204mA.
When charging is completed, the BBIC (IC201) of the portable station set the Q103-Base to "High", then Q102 is turned off. As
a result, the charging current is stopped.
4.5.

Signal Route

To measure the charge-current,R616-619 transfer the current to a voltage.
When the charge-current is 200mA,the voltage is 0.05V.
IC602 amplifies the voltage to 24.5time,then the output voltage is 24.5X0.05=1.225V.
IC601 is DC/DC convertor.This IC adjusts CII to 1.25V.
Then the charge current is adjusted to 204mA.
When charging is completed, the BBIC (IC201) of the portable station set the Q103-Base to "High", then Q102 is turned off. As
a result, the charging current is stopped.
9
KX-TCA256X