Technical Parameters 6.1906.1 Technical ParametersTelephone ParametersParameter Value ConditionsMinimum line current 15 mA off-hookMinimum line voltage 22 V on-hookOff-hook DC voltage drop < 8 V< 16 VI = 25 mAI = 50 mAOff-hook resistance >1MΩ U = 25..100VOff-hook impedance 220 Ω + 820Ω paral. 115nF20 to 60 mAReturn loss > 14 dB 20 to 60 mABandwidth 300 to 3500Hz 20 to 60 mARinging impedance > 2 kΩC = 1 μF 25 to 50 HzRinging detector sensitivity 10 to 20 V 25 to 50 HzPulse dialling 40 / 60 msDTMF dialling level 6 a 8 dB ± 2dB 20 to 60 mADial-tone detector sensitivity approx. 43dBOvervoltage protection- betweenA, B 1000 V 8 / 20 μsNotes All the product parameters comply with TBR-21 on condition that theproduct is to be operated as a single line terminal, i.e. no parallelconnection with any other equipment is allowed. Line interference and noise picked up by the LN microphone are relevantfactors.
