Technical Parameters 5.1685.1 Technical ParametersTelephone ParametersParameter Value ConditionsMinimum required off-hook line current 15 mA Off-hookMinimum required on-hook line voltage 20 V Hang-upDC voltage drop (off-hook) < 8 V< 16 VI = 25 mAI = 50 mALead current while hang-up < 25 μA U = 60 VOff-hook AC impedance 220 Ω + 820 Ω115 nF parallel20 to 60 mAReturn loss > 10 dB 20 to 60 mABandwidth 300 to 3500 Hz 20 to 60 mARinging impedance > 2 kΩC = 1 μF25 to 50 HzRinging detector sensitivity 10 to 20 V 25 to 50 HzTime of response to ringing VariablePulse dialling 40 / 60 ms 20 to 60 mADTMF level -6 and -8 dB± 2 dB20 to 60 mADTMF detector sensitivity Min. -40 dB 20 to 60 mADial tone detector sensitivity Min. -40 dB 350 - 500 HzBusy tone detection speed Variable 350 - 500 HzContinuous tone detection speed Variable 350 - 500 HzRinging tone detection speed Variable 350 - 500 HzOvervoltage protection – common mode 1000 V 8 / 20 μsOvervoltage protection – between A, Bconductors1000 V 8 / 20 μs
