4. Technical Parameters
Telephone Parameters
Parameters
Value
Conditions
Minimum required off-hook line current
15 mA
Off-hook
Minimum required on-hook line voltage
20 V
Hang-up
DC voltage drop (off-hook)
< 8 V < 16 V
I = 25 mA
I = 50 mA
Lead current while hang-up
< 25 μA
U = 60 V
Off-hook AC impedance
220 Ω + 820 Ω 115 nF parallel
20 to 60 mA
Return loss
> 10 dB
20 to 60 mA
Bandwidth
300 to 3500 Hz
20 to 60 mA
Ringing impedance
> 2 kΩC = 1 μF
25 to 50 Hz
Ringing detector sensitivity
10 to 20 V
25 to 50 Hz
Time of response to ringing
Variable
Pulse dialling
40/60 ms
20 to 60 mA
DTMF level
−6 and −8 dB ±2 dB
20 to 60 mA
DTMF detector sensitivity
Min. −40 dB
20 to 60 mA
Dial tone detector sensitivity
Min. −40 dB
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