5.4 Grounds

Pin

 

Name

 

Direction

 

Function

 

 

 

 

 

 

 

2

 

GND

 

-

 

Ground

4

 

GND

 

-

 

Ground

6

 

GND

 

-

 

Ground

8

 

GND

 

-

 

Ground

10

 

GND

 

-

 

Ground

12

 

GND

 

-

 

Ground

60

 

AREF

-

 

Analogue reference

There are two ground connections in the wireless modem, AREF (analogue ground) and GND (digital ground). Pin assignments are shown in the table above.

AREF and GND are connected at a single point inside the wireless modem, however they must not be joined together in the user application.

NOTE

5.4.1 Analogue Ground (AREF)

AREF is the return signal, or analogue audio reference, for AUXI and AUXO. These two signals provide a single-ended auxiliary audio input (host to module) and output (module to host). AREF is connected to the common GND inside the wireless modem only. The application must not connect GND and AREF.

Parameter

 

Limit

 

Unit

 

 

 

 

 

Maximum current (IMAX)

12.5

 

mA

5.4.2 Common Ground (GND)

GND is the reference, or return signal, for all system interface digital signals, radio section power, and is also the DC return for the power supply, VCC.

To carry the high current drawn by the wireless modem, the user application circuitry should connect all GND pins together.

Parameter

 

Per Pin

 

Total

 

Unit

 

 

 

 

 

 

 

Maximum current (IMAX)

 

600

 

3600

 

mA

Maximum average current (IAVG)

100

600

 

mA

LZT 123 1834

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