Bt8370/8375/8376
4.0 Applications
Fully Integrated T1/E1 Framer and Line Interface
4.1 External Component Specifications
Figure 4-4. Option D: Short Haul Interface Application
6()
3()
5()
2()
1()
1()
5()
NOTE(S):
(1)
Chip side secondary surge protection. Diodes should be low capacitance, fast turn-on Schottky or surge protection diodes.
These components are: 1. Schottky Diode—11DQ04 (disrete) or 10BQ040 (surface mount) International Rectifier, 2. two
2.1 Ω, 1/4 W, 1% Resistors. The two 470 Ω resistors in series with RTIP/RRING are used to limit the current going into the
device while the power is off and T1/E1 lines are connected.
(2)
(3)
(4)
Optional programmable receive termination –75/100/120 Ω.
Optional fixed transmit termination. The value shown provides acceptable transmit return loss for T1 and E1 applications.
Required fixed receive termination. The parallel combination of the fixed termination and programmable termination must
match the line impedance.
VSET Resistor. The VSET resistance value controls the transmit signal amplitude.
The Physical area between the connector and chokes should be kept small in order to avoid high frequency coupling and to
improve emissions test
(5)
(6)
N8370DSE
Conexant
4-9
CONEXANT [ CONEXANT SYSTEMS, INC ]
