Nortel NT1R20, Description

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QPC192 Off-Premise Extension (OPX) Analog Line Card Page 233 of 290
Line cards Description
Electrical specifications
This section lists the electrical characteristics of the OPX analog line card.
Analog line interface
Table 62 shows the electrical characteristics of the analog line interface.
Table 62
OPX analog line card—line interface unit electrical characteristics
Characteristic Specification
Terminal impedance (TIMP) 600 or 900 ohms
Balance impedance (BIMP) 600 or 900 ohms
DC signaling loop length (max)
with five ringers
750-ohm loop (excluding resistance
of telephone set) with nominal battery
of –48 V dc
DC signaling loop length (max)
with one ringer
1400-ohm loop (excluding resistance
of telephone set) with nominal battery
of –48 V dc
Battery supply voltage –2 to –52.5 V dc
Minimum detected loop current 20 mA
Line leakage Š 30k ohms, tip-to-ring,
tip-to-ground, ring-to-ground
Ring Trip During silent or ringing intervals
Signaling Loop start
Insertion Loss 5, ±1 dB at 1020 Hz