Rainbow Electronics MG260 - Manual (Page 31)

MG260 Product Specification
This document is the sole and exclusive property of FLYFOT. Not to be distributed or divulged without prior written
agreement.
Pin # Multiplex 1 Multiplex 2 Reset State Comments
69 BUZ Open collector
70 SIM_PRES Input
71 GSM_DCD1 Input
72 FLASH_LED Input
73 GPIO4 Input
74 GSM_RI1 Input
75 VBATT Input
76 VCC_RTC Input
77 VBATT Input
78 VBATT Input
79 VBATT Input
80 VBATT Input
2.5 Common GSM/GPS interface
2.5.1 Power supply
2.5.1.1 Main power supply
MG260 is powered by a single power supply signal VBATT, for both GSM and GPS
functions.
Pin
description
Signal Pin # I/O I/O type Description
VBATT 75
77
78
79
80 I Supply Main power supply
The power supply constraints for GPS are not critical compared to GSM/GPRS.
Actually, the power supply is one of the key issues in the design of a GSM/GPRS
application. Due to the bursted nature transmission, the power supply must be able to
deliver high current peaks in a short time.
The GSM RF Power Amplifier current flows with a ratio of:
e Max current 1/8 of the time (around 577 µs every 4.615 ms for GSM/GPRS class 2