Alert Loudspeaker Port; Differential Loudspeaker Circuit; Single-Ended Loudspeaker Circuit - Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger Developer's Manual

Audio Interface

Alert Loudspeaker Port

The alert loudspeaker is the default C24 power-up ringer. It is used for, but not limited to,
sounding the C24 alerts, melodies, and rings. It is located at pins 63 and 65 on the C24 interface
connector, named ALRT_N and ALRT_P respectively.
It is designed with an internal amplifier supplied directly from VCC, which supplies 0.5W to the
audio device. It may also be used as a single-ended output referenced to the C24 analog ground.
Figure 2-19
specifications.
Figure 2-19: Differential Loudspeaker Circuit
Important:
Figure 2-20: SIngle-ended Loudspeaker Circuit
30
shows the alert loudspeaker circuit and
For safety regulations it is important to place series resistors on the alert output
lines, as illustrated in Figure
design stage, but may be changed to a different value during audio safety testing, in
case that alert level limitation is required.
C24 Module Hardware Description
Table 2-9 gives the loudspeaker
2-19. The resistors value should be R = 0 at the
Ω
December 15, 2008