Enfora GSM2218, GSM2218PB001MAN 2.4 Audio In/Audio Out

GSM2218PB001MAN - GSM/GPRS MT-GL User Manual Page 13

The only way of connecting the microphone/speaker is via pins 3 - 6 of the 12-pin connector.

Please follow the specifications as listed in the table below. Enfora is not liable for damage to the MT-GL caused due to user error.

Ear – Speaker Output:

Parameter Conditions MIN TYP MAX

UNIT

Maximum Input Range –

Mic(+) to Mic(-) Inputs 3 dBm0 (Max. digital

sample amplitude when PGA

gain set to 0 dB)

32.5

mVrms

Nominal Ref. Level –

Mic(+) to Mic(-) -10

dBm0

Differential Input

Resistance –

Mic(+) to Mic(-)

100

kΩ

Microphone Pre-Amplifier

Gain 25.6

Bias Voltage on Mic(+) 2.0 or 2.5 V 2.0 2.5

Vdc

Mic Bias Current Capability 0 0.5

Handset Speaker Output

Parameter Conditions MIN TYP MAX UNIT

Maximum Swing –

Ear(+) to Ear(-) RL = 32 Ω & 5% distortion 1.2 1.5 Vpp

Maximum Capacitive Load –

Ear(+) to Ear(-) 100 pF

Amplifier Gain 1 dB

Amplifier State in Power Down High Z

Table 2 - Audio Settings