KX-TDA620BX (serv.man8) - Panasonic PBX Service Manual Supplement (repair manual). Page 11

11

The back board (BB) connects signals between optional card in KX-TDA620. It also supplies power from the power supply unit
to the cards.
Connectors Explanation
(1) Power Supply Unit Connector: CN100
(2) Free Slot Connectors: CN101 to CN111
(3) BUS-S Card Connector: CN112
(4) FAN Connector: CN115
(5) LED Connector: CN114
(6)Voltage drop Resistor for Fan control: R400

CCLINK_RXD

CircLink receive data

CCLINK_TXEN

CircLink send data valid

CLK_20M

CTSW operating clock (20.0MHz)

SHWU[2:0]

Intersystem highway upstream data

SHWD[2:0]

Intersystem highway downstream data

SHWU[2:0]_P/N

Intersystem highway upstream differential signal

SHWD[2:0]_P/N

Intersystem highway downstream differential signal

SHW_CLK_P/N

Intersystem clock differential signal

SHW_nFH_P/N

Intersystem frame timing differential signal

S_RINGSYNC_P/N

Ringer synchronous differential signal 

S_nRESET_P/N

Extension shelf reset differential signal

CT_NETREF_P/N

Differential signal of the extension shelf synchronous reference signal 

CCLINK_P/N

Circlink communication differential signal

nLOS_P/N

Differential signal for loss of line indicator

CPU_STATUS[1:0]_P/N

Differential signal for BUS-S status

nSLF_PRS

Extension shelf connection display signal

S_ESLFID[1:0]

Extension shelf ID notification signal

+15V

Power supply

3.3V

IC power supply on the card 

3.3VB

Backup power supply (3.3V)

1.5V

Power supply for CPU (IC200)