PANASONIC KXTG4000B
Manual de Servicio

and DCSENSE (pin 118 of IC1). With a standard input of 2.4 V, an output voltage of 3.8 V is generated. EXTR (pin 114 of IC1) is the port for Q6 control, and DCSENSE (pin 118 of IC1) is the standard input port of the DCDC converter.CMR (pin 118 of IC1) is the port for L1 current control. It uses R64/0.1 to limit the current to 1.9 A.

Regulator This is comprised of Q7, D21, C31, C34, C35 and LRTR (pin 121 of IC1), LRCC (pin 122 of IC1) LRSENSE (pin 120 of IC1). Input of 3.8 V is regulated to 2.65 V. LRTR (pin 121 of IC1) is the port for Q7 control, LRCC (pin 122 of IC1) is the port for AC input to the regulator, and LRSENSE (pin 120 of IC1) is the standard input port.

LIM (pin 112 of IC1) is the port for battery limiter control. It is this port which controls Q5 and controls input to VDDB (pin 109 of IC1). ADBAT (pin 141 of IC1) is the port that monitors the battery voltage. It detects battery LOW if the voltage is 2.35 V or less. VDD EEPROM (pin 53 of IC1) is the power output port for the external EEEPROM.

The power for sounding from ringer is supplied from Battery. The signal for driving the ringer is supplied from pin88 of Baseband IC1, and turns Q1 ON and OFF. The ringer volume is controlled by the Pulse Width of the signal. The ringer volume can be switched between HIGH and LOW. The volume is controlled by changing the duty ratio of the signal output from pin 88 of IC1.

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