SPM and Security Subsystem

FX651

© 1997 Consumer Microcircuits Limited

12

D/651/4

Notes:

4.

Small signal impedance.

5.

At output of smoothing network.

6.

7.

8.

The time between a logic "1 - 0" transition at NRZ data input and the tone at TXOP

reaching 10% of its full value or between a "0 - 1" transition at NRZ data input and the

tone falling to 90% of its full value.

9.

The time for the 18kHz tone at TXOP to rise from 10% to 90% or to fall from 90% to

10% of its full value.

10.

11.

Maximum 10% distortion for incoming SPM tone, not including interfering speech or

security tone (16kHz - 20kHz).

Minimum SNR 22dB for incoming SPM tone.

12.

Signal levels at the line side of the input capacitor. 12kHz channel performance

specified in the presence of the following interfering signals:

(a)

A 1.2V tone in the frequency range 16kHz - 20kHz.

(b)

An ordinary speech signal containing frequencies in the range

300Hz - 3400Hz of maximum instantaneous amplitude 8.0Vpk-pk.

13.

The device responds after 40-50ms of continuous valid tone and de-responds after: a

40-50ms period of no-tone, tones less than 25mV or an out of band tone.

14.

Maximum 10% distortion for incoming security tone, not including interfering SPM tone

(11kHz - 13kHz).

Minimum 20dB SNR for incoming security tone.

15.

Signal level specified at the line side, i.e. before the input capacitor. Performance

specified in the presence of an interfering 800mV tone in the frequency range 11kHz -

13kHz.

16.

The device responds after 8ms of continuous valid tone and de-responds after: a 8ms

period of no-tone, tone of 10mV or less, or an out of band tone.