Common electrical specifications (United States version)

 

Specification

Description

Connectors

RJ-21x

Return loss (ref. 600 Ohms +2.2 uF standard)

20 dB min. (ERL)

4 to 2 wire gain Tolerance

+/- 1 dB

4 to 2 wire gain range

+6 to -6 dB

2 to 4 wire gain Tolerance

+/- 1 dB

2 to 4 wire gain range

+6 to -6 dB

Frequency response
300 Hz - 3200 Hz. Reference to 1 kHz

+/- 1 dB

Trans-hybrid loss

17 dB min. @ 300 Hz-3.0 KHz into 600 Ohms + 2.2 uF

Signal overload level

+3 dBm at 0 dB gain

CMRR

> 80 dB

T-R input impedance
(300 - 3200 Hz)

Voice band 600 Ohms +2.2 uF standard

Idle channel noise through connection

< 20 dB rnC

Crosstalk transmit to receive channels

< -70 dB @ 1 kHz

T-R isolation to SELV

>1500VRMS

Off-hook detect

Guaranteed Detect : Current > 10 mA

Guaranteed No Detect: Current < 3.3 mA

Operating loop current

18 mA to 70 mA

Loop current and polarity detect

Single bit indicates if the current is flowing from Tip to Ring or Ring to Tip.

Ring detection

Guaranteed Detect: 30 VRMS 17 - 33 Hz (US version)

Guaranteed No Detect: No detect <15 VRMS (0 - 5 kHz)