User's Manual

M590 GPRS Module Hardware User Guide

2.38<V

<2.8

SMS and Incoming Call Ring

10 RING DO Ring output I/PD

0<V

<0.6

2.1<V

<3.1

0<V

<0.42

2.38<V

<2.8

Detect incoming

SMS messages or

calls

ADCDetecting

16 ADC_IN AI 10-bitADC input

Detectable voltage

range: 0 V to 2.8 V

GPRS Antenna

21 GPRS_ANT

AI/O

GPRS antenna

interface

50 Ω impedance

Reserved Pins

17 NC

Must be left

disconnected.

P: indicates power supply pins

NC: indicates pins that are not supported and must not be connected

DI: indicates digital signal input pins

DO: indicates digital signal output pins

I/PD: indicates digital signal input pins with pull-down

I/PU: indicates digital signal input pins with pull-up

AI: indicates analogy signal input pins

AO: indicates analogy signal output pins

The maximum input voltage at all IO ports (including peak signal current) cannot exceed 3.1 V because

the module uses a 2.8 V IO power system. In the application of the module, the IO output voltage from the

3.3 V power supply system of the external circuit might greatly overshoot 3.1 V due to the signal integrity

design. In this situation, the IO pins of the module might be damaged if the IO signals are connected to the

IO port on the 2.8-V system. To rectify this issue, take measures to match the level. For details, see the

Section 3.2 UART.