Nortel Networks Circuit Card - Manual (Page 531)

NT8D02 and NTDK16 Digital Line cards Page 531 of 906
Circuit Card Description and Installation
Figure 105
Digital line card – block diagram
Digital
line
interface
Micro-
controller
5.12 MHz clock
Tx PCM
DS-30X loop
Card
LAN link
Power
supplies
Front
panel
LED
Card LAN
interface
Tip
TCM
loop
interface
circuit
Digital
phone lines
Line interface units 0–7
Line interface units 8–15
Ring
Tip
TCM
loop
interface
circuit
Digital
phone lines
Ring
Rx PCM
1 kHz frame sync
Card slot
address
Sanity
timer
553-6163
Digital
line
interface
+ 5 V dc
+10 V dc
±15 V dc
Reg
+15 +10
+10 V dc
Address/
data bus