DS21448L+ Maxim Integrated Products, DS21448L+ Datasheet - Page 36
![IC LIU QUAD E1/T1/J1 128-LQFP](/photos/6/82/68247/128-lqfp_21-0086d_sml.jpg)
DS21448L+
Manufacturer Part Number
DS21448L+
Description
IC LIU QUAD E1/T1/J1 128-LQFP
Manufacturer
Maxim Integrated Products
Type
Line Interface Units (LIUs)r
Datasheet
1.DS21448L.pdf
(60 pages)
Specifications of DS21448L+
Number Of Drivers/receivers
4/4
Protocol
T1/E1/J1
Voltage - Supply
3.135 V ~ 3.465 V
Mounting Type
Surface Mount
Package / Case
128-TQFP, 128-VQFP
Product
Framer
Number Of Transceivers
4
Supply Voltage (max)
3.465 V
Supply Voltage (min)
3.135 V
Supply Current (max)
400 mA
Maximum Operating Temperature
+ 70 C
Minimum Operating Temperature
0 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
TRANSMIT LINE
RECEIVE LINE
Figure 7-1. Basic Interface
NOTE 1: ALL RESISTOR VALUES ARE ±1%.
NOTE 2: IN E1 APPLICATIONS, THE R
NOTE 3: THE RR RESISTORS SHOULD EACH BE SET TO 60Ω IF THE INTERNAL RECEIVE-SIDE TERMINATION FEATURE IS ENABLED. WHEN THIS
NOTE 4: SEE
(Table
FEATURE IS DISABLED, R
Table 7-A
7-A). NO RETURN LOSS IS REQUIRED FOR T1 APPLICATIONS.
AND
TOWARD THE NETWORK)
Table 7-B
(LARGER WINDING
R
= 37.5Ω FOR 75Ω OR 60Ω FOR 120Ω E1 SYSTEMS, OR 50Ω FOR 100Ω T1 LINES.
T
FOR THE APPROPRIATE TRANSMIT TRANSFORMER TURNS RATIO (N).
2:1
1:1
RESISTORS ARE USED TO INCREASE THE TRANSMITTER RETURN LOSS
R
r
R
R
t
t
(NONPOLARIZED)
R
0.1µF
r
1.0µF
36 of 60
RTIP
TTIP
RRING
TRING
Semiconductor
DS21448
Dallas
DS21448 3.3V T1/E1/J1 Quad Line Interface
MCLK
V
V
V
V
DD
DD
SS
SS
0.01µF
(THIS CAN ALSO BE 1.544MHz
FOR T1 ONLY OPERATION)
0.1µF
0.1µF
2.048MHz
0.01µF
V
10µF
DD
+
68µF