DS2148T+ Maxim Integrated Products, DS2148T+ Datasheet - Page 50

• Manufacturer Part Number: DS2148T+
• Description: IC LIU E1/T1/J1 5V 44-TQFP
• Manufacturer: Maxim Integrated Products
• Type: Line Interface Units (LIUs)r

Specifications of DS2148T+

• Number Of Drivers/receivers: 1/1
• Protocol: T1/E1/J1
• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 7-2. Protected Interface Using Internal Receive Termination
NOTES:
1)
2)
3)
4)
5)
6)
7)
8)
9)
All resistor values are ±1%.
C1 = C2 = 0.1µF.
S is a 6V transient suppresser.
D1 to D8 are Schottky diodes.
The fuses are optional to prevent AC power line crosses from compromising the transformers.
Rp resistors exist to keep the Fuses from opening during a surge. If they are used, then the 60Ω receive termination resistance must
be adjusted to match the line impedance.
The Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications.
The transmit transformer turns ratio (N) would be 1:1.36 for 5V operation.
The 68µF is used to keep the local power plane potential within tolerance during a surge.
Transmit
Receive
Line
Line
Fuse
Fuse
Fuse
Fuse
(optional)
(optional)
Rp
Rp
Rp
Rp
toward the network)
(larger winding
N:1
1:1
0.1uF
60
S
S
Rt
Rt
polarized)
0.47uF
(non-
60
D3
D1
D5
D7
50 of 73
C1
C2
+VDD
+VDD
D6
D8
D2
D4
TTIP
TRING
RTIP
RRING
DS2148
VDD (21)
VSS (22)
VSS (35)
VDD (36)
MCLK
0.01uF
0.1uF
0.1uF
2.048MHz
(this clock can also
be 1.544MHz for T1
only applications)
10uF
10uF
+VDD
68uF