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KX-MB2110RUW/ KX-MB2130RUW/ KX-MB2170RUW/ KX-MB2117RUB/ KX-MB2137RUB/ KX-MB2177RUB
6.17. Main Board Power Supply Section
6.17.1.
3.3V and 1.2V Power Supply Descriptions
1. IC800, IC801 is Synchronous Step-Down DC/DC Converter.
2. Fixed Frequency Operation : 340kHz
3. Q803, R809, Q804, R815, C812, R816 are Sequence circuit.
2. Fixed Frequency Operation : 340kHz
3. Q803, R809, Q804, R815, C812, R816 are Sequence circuit.
(After the 1.2V DC/DC converter is turned on, the 3.3V DC/DC converter turns on.)
4. D803, D801 are the Zener Diode for Over voltage protection.
6.17.2.
5V Power Supply Descriptions
1. IC802 is low dropout three-terminal regulator.
2. D806 is the Zener Diode for Over voltage protection.
2. D806 is the Zener Diode for Over voltage protection.
6.17.3.
2.5V Power Supply Descriptions
1. IC803 is low dropout three-terminal regulator for SPT.
R803
F24k
C825 NC
(
)
C813
K3300p
C814
K0.1u(1608)
D801
C871
NC
()
LVIN
+1.2V
+1.2V
L801 4.7u
IC800
2 VIN
8 SS
3
SW
4
GND1
5
FB
7 EN
1
BOOT
6 COMP
9
GND2
R842 NC
(
)
C816
47u/6.3V
R811 F12k
C810
K0.1u(1608)
R855 100k
R854
3.3k
C8081 0u/25V
Q804
R815
10k
R816 1k
C812 10u/10V
Q803
R809
10k
+5VD
R802
0(2125)
S3.3V
Q800
()
NC
+3.3V
+3.3V
C805
K0.1u(1608)
IC801
2 VIN
8 SS
3
SW
4
GND1
5
FB
7 EN
1
BOOT
6 COMP
9
GND2
C824 NC
(
)
(
)
C800 NC
( )
C803
K0.1u(1608)
R806 F75k
C870
NC
()
R839
NC
(
)
LVIN
D803
R804
F24k
C807
47u/6.3V
PWRDWN2
R820
NC
()
C804
K3300p
R841 NC
+1.2V
L800 10u
R853
12k
C801
10u/25V
D805
(
)
NC
D806
LVIN
IC802
3 IN
2
OUT1
1
ADJ
4
OUT2
R822
F120
R821
F360
+5VD
C820
22u/6.3V
C819
10u/25V
+5V
+2.5VT
C835
NC
()
C836 NC
()
R844
NC
()
R843
NC
()
IC803
NC
3 IN
2
OUT1
1
ADJ
4
OUT2
+5VD
+2.5V(SPT)
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