User's Manual

Neo_GM650 User Manual V1.0

5 Pin Definition & Encapsulation

5.1 Pin Definition

The signal connection uses 74pin SMD pad of stamp hole(half hole).

Note: GM650 module IO interface level is 2.8V.

Because the module IO uses 2.8V power supply system, the maximum input voltage of all

the IO interface can not exceed the maximum 3.3V, otherwise it may damage the module

IO. Considering the signal integrality designing reasons,while the external circuit use 3.3V

power system the IO interface output voltage will exceed 3.3V because of overshoot

phenomenon, sometimes can even reach 3.5V.Therefore,the IO pin of the module will be

damaged if 3.3V IO signal is connected to 2.8V IO of the module directly.So it is needed to

adopt level matching measures.Please refer to chapter 6.2.

Table 5-1 GM650

Pin Definition

Signal Name

I/O Function Description

Remark

1 GND

PWR

Ground

2 Reserved

Reserved

3 Reserved Reserved

4 URXD1 DI UART1 data receiving

UTXD1

UART1 data transmitting

Used to GPRS communications

and AT commands

6 NC

Reserved

suspend, without any signal input.

7 UTXD2

UART2 data

transmitting, baud rate

= 9600

Dual-port mode, used to receive

GPS data;

Single-port mode, suspend.