Rainbow Electronics GE863-PY User Manual

Page 20

GE863 Hardware User Guide

1vv0300783 Rev.0 - 10/06/08

page 20 of 80

In case of GE863-GPS with p/n 3990250690 the GPS consumptions are reduced by a 30%:

GE863-GPS (3 990 250 660)

GE863-GPS (3 990 250 690)

Operating current

70 mA

±20%, including 50 mA for the

GPS hardware and 20 mA for the

antenna LNA

55mA, including 35mA GPS for the

GPS hardware and 20 mA for the

antenna LNA

GE863-QUAD/PY/SIM

Mode

Average (mA)

Mode description

IDLE mode

Stand by mode; no call in progress

AT+CFUN=1

24,0

Normal mode: full functionality of the module

AT+CFUN=4

22,0

Disabled TX and RX; module is not registered on the network

AT+CFUN=0 or

AT+CFUN=5

7,20 / 3,56

Power saving: CFUN=0 module registered on the network and can

receive voice call or an SMS; but it is not possible to send AT

commands; module wakes up with an unsolicited code (call or

SMS) or rising RTS line. CFUN=5 full functionality with power

saving; module registered on the network can receive incoming

calls and SMS

RX mode

1 slot in downlink

53,0

2 slot in downlink

66,0

3 slot in downlink

79,0

4 slot in downlink

89,0

GSM Receiving data mode

GSM TX and RX mode

Min power level

78,0

Max power level

200,0

GSM Sending data mode

GPRS (class 10) TX and RX mode

Min power level

124,0

Max power level

371,0

GPRS Sending data mode

The GSM system is made in a way that the RF transmission is not continuous, else it is packed into
bursts at a base frequency of about 216 Hz, and the relative current peaks can be as high as about
2A. Therefore the power supply has to be designed in order to withstand with these current peaks
without big voltage drops; this means that both the electrical design and the board layout must be
designed for this current flow.
If the layout of the PCB is not well designed a strong noise floor is generated on the ground and the
supply; this will reflect on all the audio paths producing an audible annoying noise at 216 Hz; if the
voltage drop during the peak current absorption is too much, then the device may even shutdown as a
consequence of the supply voltage drop.

TIP: The electrical design for the Power supply should be made ensuring it will be capable of a peak current output
of at least 2 A.

Worst/best case depends on network configuration and is not under module control