Panasonic KX-MB262CX Service Manual page 24

Temperature AD value
°
[C ]
20 102
21 100
22 97
23 95
24 93
25 91
26 88
6.17. Main Board Section
3.3V Power Supply descriptions
• IC 302 decreases the output voltage when NPN transistor installed chopper amplifier type switching regulator produces 2.3A min
or over at the output voltage.
Oscillation frequency is set at approximately 500kHz.
• C375 and D302 are boost circuits as a base driving voltage for buit-in transistors.
• D301,R311,R312,R313,C375,Q300,R318,Q301are UVLO (Under Voltage Lock Out) circuit.
Q301 turns on when the in-out voltage is 17V or less and SS/SE terminal becomes low so that IC302's operation is stopped.
• D303 controls no to be a over voltage at 3.3V output when ICs including IC302 break down.
1.2V Power Supply descriptions
• IC305 is Nch FET used Switching Regulator with synchronous rectification system.
Oscillation frequency is set at approximately 350kHz.
• R356 is a resistor for decreasing the output voltage when the output current shows high.
The value is compared with the voltage drop at FET.
• C395 and D305 are FET's boost circuit as a gate driving voltage.
HEX reading Temperature
°
[C ]
66 67
64 68
61 69
5F 70
5D 71
5B 72
58 73
AD value HEX reading
30 1E 114
29 1D 115
28 1C 116
27 1B 117
27 1B 118
26 1A 119
25 19 120
KX-MB262CX/KX-MB772CX
Temperature AD value HEX reading
°
[C ]
9 09
9 09
9 09
8 08
8 08
8 08
8 08