Nortel Circuit Card Installation Manual page 531

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