9-130

MH89726/728

Advance Information

Table 1 - Typical Transmission Performance at 160 kbit/s

Table 2 - Typical Transmission Performance at 80 kbit/s

Note 1: The attenuation of the cable as specified by Bell System Technical Reference PUB 62411.

Figure 4 - Typical Application of the Loop Extender

MH89726 (160 kbit/s)

CABLE

CONFIGURATION

24 AWG

(8.0 dB/km at 120 kHz)

26 AWG

(11.5 dB/km at 120 kHz)

DNIC to DNIC

0.0 to 4.1 km

0.0 to 3.0 km

DNIC with LEC to DNIC with LEC

0.65 to 5.1 km

0.5 to 3.6 km

MH89728 (80 kbit/s)

CABLE

CONFIGURATION

24 AWG

(6.9 dB/km at 60 kHz (Note 1)

26 AWG

(10.0 dB/km at 60 kHz)

DNIC to DNIC

0.0 to 5.2 km

0.0 to 3.4 km

DNIC with LEC to DNIC and LEC

0.9 to 6.5 km

0.65 to 4.1 km

1

+5V

21

D1

D2

CA

CB

RA

LOOP

EXTENDER

and

Network

Termination

MT8972

0.33

µF

1.0

µF

2:1

Twisted Pair

Copper 24-26

Gauge

NOTES:

-D1, D2 IN5817 (Schottky)

-Solid jumpers used to connect the loop extender

-Dotted jumpers connect MT8972 without loop extender

80 kbit/s RA = 390

Ω CA = 22nF CB = 3.3nF

160 kbit/s RA = 390

Ω CA = 22nF CB = 1.5nF