Hardware interfaces
Version 8 dated 15.03.00
25
Siemens Information and Communication Products
4.4
Audio interface
Note:
1
) F
scale
= 10^((3*inBbcGain)/20) (for parameter "inBbcGain", see description of command AT^SNFI in Chapter
mens-defined AT commands for enhanced functions” on page 111
The microphone should comply with the following technical data:
Technical data of the speaker:
Signal
Function
I/
O
Level
Comments
MICP
Microphone plus
I
Vpp(V):
1
)
typ.: 1.0954 / F
scale
max.: 1.578 / F
scale
Differential input; must be AC-coupled;
input resistance: 11–22 M
Ω
Note: may be disconnected if unused
MICN
Microphone minus
I
Vpp(V):
1
)
typ.: 1.0954 / F
scale
max.: 1.578 / F
scale
Differential Input; internally; must be AC-coupled; in-
put resistance: 11–22 M
Ω
Note: may be disconnected if unused
SPP
Speaker plus
O
Vpp(V):
nom.: 2.1909
max.: 3.156
min. load resistance: 32
Ω
max. load capacitance: 100 pF
should be AC-coupled
Note: may be disconnected if unused
SPN
Speaker minus
O
Vpp(V):
nom.: 2.1909
max.: 3.156
min. load resistance: 32
Ω
max. load capacitance: 100 pF
should be AC-coupled
Note: may be unconnected if unused
BUZZER
Buzzer
O
1.2 V - 1.35 V
> 2 kOhm, < 50 pF,
used only with integrated MMI
Note: may be disconnected if unused
HOOKSW Hookswitch
I
2.8 V
used only with integrated MMI
ON-HOOK = 0V
OFF-HOOK = 2.1 - 3 V
if unused, connect to a 10 kOhm - 100 kOhm pull-down resi-
stor
Sensitivity
-37
±
2 dB (500 Hz, 0 dB = 1 V/Pa, v = 0)
Impedance
2 k
Ω
±
30% (1 kHz)
Bias voltage
1.5 V DC (1–10 V DC)
Input current
≤
300
µ
A
Signal-to-noise ratio
≤
66 dB
Volume
(97.0
±
2) dB SPL
Impedance
150
±
30
Ω
THD
≤
4% (800 Hz, 104 dB SPL)
≤
2% (300–3400 Hz, 94 dB SPL)