Gemalto M2M GmbH MC56 User Manual

MC55/56 Hardware Interface Description 
Confidential / Preliminary 

s

 

MC55/56_hd_v03.00 

Page 89 of 104 

16.08.2005 

Test conditions: 
•  The values specified below were tested to 1kHz and 0dB gain stage, unless otherwise 

stated.  

•  Parameter setup: Audio mode = 5 for MICP1 to MICN1 and 6 for MICP2 to MICN2, 

inBbcGain= 0, inCalibrate = 32767, outBbcGain = 0, OutCalibrate = 16384, sideTone = 0 

 

Table 31: Voiceband transmit path 

Input voltage (peak to peak) 

MICP1 to MICN1, MICP2 to 
MICN2 

 

 

1.03 

V 

 

 

Input amplifier gain in 6dB steps 
(inBbcGain) 

0 

 

42 

dB 

Set with AT^SNFI 

Fine scaling by DSP (inCalibrate)  -∞ 

 

0 

dB 

Set with AT^SNFI 

Input impedance MIC1 

 

50 

 

kΩ 

 

Input impedance MIC2 

 

2.0 

 

kΩ 

 

Microphone supply voltage ON 
Ri = 4kΩ (MIC2 only) 

2.57 
2.17 
1.77 

2.65 
2.25 
1.85 

2.73 
2.33 
1.93 

V 
V 
V 

no supply current 
@ 100µA 
@ 200µA 

Microphone supply voltage OFF; 
Ri = 4kΩ (MIC2 only) 

 

0 

 

V 

 

Microphone supply in POWER 
DOWN mode