U4089B-P_05 Datasheet, PDF (9/26 Pages) ATMEL Corporation – Monolithic Integrated Feature Phone Circuit

U4089B-P
5. Operating Range of Speaker Amplifier
The basic behavior is illustrated in Figure 5-1. Actual values of IL_ON/IL_OFF vary slightly with the
adjustment of the DC characteristics and the selection of the internal line impedance.
Figure 5-1. Threshold of Speaker Amplifier
SA _on
SA _off
IL _off
IL _{on IL}
Figure 5-2. Comparator Thresholds Depend on DC Mask and Line Impedance
7
RDC = ∞
6
RDC = 130 k
5
RDC = 68 k
4
3
10.0
12.0
14.0
16.0
18.0
20.0
I _L ( mA )
= ILON at line impedance = 600 Ohm
= ILOFF at line impedance = 600 Ohm
= ILON at line impedance = 900 Ohm
= ILOFF at line impedance = 900 Ohm
9
4518C–CORD–10/05