Data Sheet
March 1997
L7554 Low-Power SLIC
Applications (continued)
Characteristic Curves (continued)
1500
1000
8
7
6
5
4
3
49 dB, RP MATCHED TO 1.5 Ω
500
2
1
0
58 dB, RP MATCHED
TO 0.5 Ω
0
0
500
1000
1500
2000
0
20
40
60
80
100
120
LOOP RESISTANCE, RLOOP (Ω)
PROTECTION RESISTOR VALUE (Ω)
12-3019 (C)
Note: VBAT = –48 V; ILIM = 22 mA; RDC1 = 113 Ω.
Figure 23. Longitudinal Balance Resistor Mismatch
Requirements
12-3052 (C)
Figure 21. 7551 Typical SLIC Power Dissipation vs.
Loop Resistance
60
55
2000
1500
50
45
40
300 cu. ft./ min.
36 °C/W
1000
STILL AIR
47 °C/W
500
0.0
0.5
1.0
1.5
2.0
2.5
PROTECTION RESISTOR MISMATCH (Ω)
0
20
40
60
80
100
120
140
180
160
12-3021 (C)
AMBIENT TEMPERATURE, TA (°C)
Figure 24. Longitudinal Balance vs. Protection
Resistor Mismatch
12-2825 (C)
Figure 22. Power Derating
Lucent Technologies Inc.
19
AGERE [ AGERE SYSTEMS ]
