DOWNLOAD Panasonic KX-NT366RU (serv.man2) Service Manual ↓ Size: 3.56 MB | Pages: 82 in PDF or view online for FREE

13

14

The lighting of the LED is controlled by IC4.
The LED lights up in a dynamic lighting system.
The duty ratio is 1/8 (ON time 1.5ms).

15

16

This Power Supply Circuit supports the power supply through an Ethernet line called PoE (Power over Ethernet) as well as the
input from a regular AC adapter. It converts the power supply from the both to 3.9V and is supplied to a 3.3V and 1.5V regulator
on the MAIN board.
The power supply circuit consists of the four sections below.

When the hub or router supporting 802.3af is connected to LAN port (JK2), the authentication voltage and the classification volt-
age are supplied between Pin 1, 2 and 3, 6 or Pin 4, 5 and 7, 8 of JK2. 
When this voltage is detected automatically by IC9, it applies the corresponding current and is identified on the hub side, so that
the hub starts to supply 48V.
In that case, as there is OR with the power from LAN port (JK2) and the power from DC jack(JK3) by D6 and D3, the power from
LAN port is supplied to the switching regulator IC8 preferentially.

This switches the power from the DC jack or LAN port by IC8 to generate 3.9V. The switching frequency is 380KHz.

C501 and C502 are super capacitor and performs backup during a temporary blackout. 
Usually, the power is stored from IC8 through D7 to C501 and C502. It is generally 4.7V and clipped by the Zener diode of D5.

If the voltage supplied to the Switching Regulator Circuit goes under (3.5V), pin1 of IC13 then goes 0V and informs the
decreased voltage for VoIP (IC1) and Sub-CPU (IC4).

DG

R93

C51

C55

C93

DG

R84

L18

DG

DG

DG

IC10

1

CE

2

GND

3

NC

4

VDD

5

VOUT

DG

DG

PHY3.3V

D3.3V

D6

D3

D7

IC8

1

NC1

2

SW

3

BST

4

ISEN

5

SGND

6

RTN

7

NC7

8

NC8

9

FB

10

SS

11

RON/SD

12

VCC

13

VIN

14

NC14

D4

DC_ALARM

DG

DG

PoE+

D2-pin(+) 48V

D2-pin(-) 48V

PoE-

C88

DG

DG

D3.3V

C95

DG

C53

C77

C62

C94

C84

C85

DG

D5

DG

D4.0V

C61

Back UP

16
15
14
13

12
11
10

9

IC13

1

VOUT

2

VIN

3

NC

4

VSS

nDETPDN

R104

C52

C83

NC

C86

DG

DG

C54

L19

A3.3V

AG

C50

AG

C113

IC31

1

VIN

2

VSS

3

CE

4

NC

5

VOUT

AG_2

C114

A3.3V

L21

NC

DG

R83

R72

R74

R73

IC9

1

NC1

2

RCLASS

3

NC3

4

VIN

5

VOUT

6

PWRGD

7

NC7

8

GND

R71

DG

DCIN+

DCIN-

R103

C112

IP2

CN1

DG

DC_JACK

C501

C502

JK3

1

2

3

DCIN+

DCIN-

DC_BACKUP

DG

R502

R501

CN501

1
2
3
4

5
6
7
8

DC+

DC-

L501

1

2

3 4

Voltage Detection Circuit

Switching Regulator Circuit

IEEE802.3af Authentication Circuit

Backup Power Supply Circuit

D3.3V