Motorola Mobility LLC T56KT1 Manual Do Utilizador

 shows the microphone circuit and 

 gives the microphone specifications.

The headset microphone circuit design depends on the type of microphone device.
A series capacitor is required in case a passive microphone is used, or the 
application provides a separate bias voltage to an active microphone circuit.
The internal G30 biasing circuit may also be used with an active microphone, which 
corresponds to the headset microphone port specifications.

The analog differential speaker port is the G30 power-up default active output for voice calls and 
DTMF tones. It is located at pins 48 and 49 on the G30 81 pin LGA interface, named SPKR_N 
and SPKR_P respectively.

It is designed as a differential output with 8Ω impedance, but may also be used as a single-ended 
output referenced to the G30 analog ground.

The differential speaker output is used for the handset audio path.

Input Voltage

No load
AT+MMICG=0

2.0

V

PP

Gain

Programmable in 
1 dB steps

0

45

dB

AC Input 
Impedance

1

kΩ

Bias voltage

R

BIAS 

= 3.0 kΩ

I

BIAS 

= 1 mA

1.8

2.0

2.2

V

Bias Current

1

mA