User Manual

GM47/48 Technical description
BA/SEM/MS 02:0004 Rev B
17
There are two ground signals in GM 47/48, Analogue Ground
(AGND) and Digital Ground (DGND). The analogue Ground is
connected to pin number 60, and the Digital Ground is connected to
the System Connector Interface through pin numbers 2, 4, 6, 8, 10 and
12.
Note: All the Ground pins have to be connected to the application.
The AGND is connected to the DGND in the ME, and only there. It is
important that the AGND and the DGND are separated in the
application.
3.3.1 The Analogue Ground
The AGND lead is the analogue audio reference ground. It is the
return signal for Audio To Mobile Station (ATMS) and Audio From
Mobile Station (AFMS).
It shall be connected to the Digital Ground (DGND) inside the module
and only there. The application shall not connect DGND and AGND.
Parameter Limit
I
max
≅12.5mA
3.3.2 The Digital Ground (DGND)
DGND is the reference for all digital signals in the System Interface.
It shall also be the DC return for the power supply on VCC and
SERVICE. Each DGND pin is rated at 0.5 A. All DGND pins are
connected internally in the module.
Parameter Limit
I
average
< 0.5 A No DGND pin can withstand over 0.5 A
I
max
< 600 mA (100 mA each)
3.4 Regulated Power Supply
Pins Name Description
1, 3, 5, 7, 9, 11 VCC Regulated Power Supply
The regulated power supply, VCC, is connected to the pin numbers 1,
3, 5, 7, 9 and 11.