GR47/48 Design Guidelines
BA/SEM/MS 03:0015 Rev A
LZT 123 7596
9
3.2 Grounding
Pins
Name
Description
2, 4, 6, 8, 10, 12
DGND
Digital Ground
60
AGND
Analogue Ground
There are two ground signals in GR 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.
3.2.1 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 is 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
3.2.2 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)
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