Motorola 8900 User Manual - Page 54

Alert Loudspeaker Port, Differential Loudspeaker Circuit

Get Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger PDF manuals and user guides
UPC - 845374028836
View all Motorola 8900 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 54 highlights

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 shows the alert loudspeaker circuit and Table 2-9 gives the loudspeaker specifications. Figure 2-19: Differential Loudspeaker Circuit Important: For safety regulations it is important to place series resistors on the alert output lines, as illustrated in Figure 2-19. The resistors value should be R = 0Ω at the design stage, but may be changed to a different value during audio safety testing, in case that alert level limitation is required. Figure 2-20: SIngle-ended Loudspeaker Circuit 30 C24 Module Hardware Description December 15, 2008

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
Audio Interface
30
C24 Module Hardware Description
December 15, 2008
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
shows the alert loudspeaker circuit and
Table 2-9
gives the loudspeaker
specifications.
Figure 2-19: Differential Loudspeaker Circuit
Important:
For safety regulations it is important to place series resistors on the alert output
lines, as illustrated in
Figure 2-19
. The resistors value should be R = 0
Ω
at the
design stage, but may be changed to a different value during audio safety testing, in
case that alert level limitation is required.
Figure 2-20: SIngle-ended Loudspeaker Circuit