User's Manual

HC864-AUTO Hardware User Guide
1vv0300946 Rev.4 – 2012-12-27
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Reserved. Page 27 of 77
5. Power Supply
The power supply circuitry and board layout are a very important part in the full product
design and they strongly reflect on the product overall performances. Read carefully the
requirements and the guidelines that will follow for a proper design.
5.1. Power Supply Requirements
The HC864-AUTO power requirements are:
Power Supply
Nominal Supply Voltage 3.8V
Max Supply Voltage 4.2V
Supply Voltage Range 3.4V – 4.2V
HC864-AUTO
Mode Average(mA) Mode Description
IDLE mode Standby mode; no call in progress
WCDMA 15.0
AT+CFUN=1
GSM 15.0
Normal mode; full functionality of the module
WCDMA 13.0
AT+CFUN=4
GSM 13.0
Disabled TX and RX; modules is not registered on the
network
WCDMA 2.7/1.0*
AT+CFUN=0 or
AT+CFUN=5
GSM 3.2/1.3*
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.
CFN=5 full functionality with power saving;
Module registered on the network can receive
incoming call sand SMS
WCDMA TX and RX mode
WCDMA Voice 630 WCDMA voice channel
HSPA 640 HSPA data channel
GSM TX and RX mode
GSM Voice 260 GSM voice channel
GPRS Class33 680 GPRS data channel
EDGE Class33 380 EDGE data channel
* Worst/best case depends on network configuration and is not under module control.
TIP:
The electrical design for the Power supply must be made ensuring that it will be capable of a
peak current output of at least 2A.
In GSM/GPRS mode, RF transmission is not continuous and 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.