Telit Wireless Solutions UC864 manual 5V Uart level translation

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UC864-E Hardware User Guide

1vv0300766a Rev.1 - 31/01/08

5V UART level translation

If the OEM application uses a microcontroller with a serial port (UART) that works at a voltage different from 2.6 – 2.9V, then a circuitry has to be provided to adapt the different levels of the two sets of signals. As for the RS232 translation there are a multitude of single chip translators. For example a possible translator circuit for a 5V TRANSMITTER/RECEIVER can be:

TO TELIT

MODULE

TIP: This logic IC for the level translator and 2.6V pull-ups (not the 5V one) can be powered directly from PWRMON line of UC864-E. Note that the TC7SZ07AE has open drain output; therefore the resistor R2 is mandatory.

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Contents UC864 Hardware User Guide This document is relating to the following products UC864-E Hardware User GuideContents 11.2 10.310.4 11.1Disclaimer Overview Length 36.2 mm Width 30 mm Thickness 8mm Mechanical DimensionsPIN-OUT UC864-E module connectionsCmos Reserved Pin Signal Function 1 UC864-E Antenna connectorTurning on the UC864-E Hardware Commands10k Hardware shutdown Turning OFF the UC864-EHardware Unconditional Restart 10k +1.8 Power Supply Requirements Power SupplyUC864-E Hardware User Guide Electrical Design Guidelines General Design Rules1.2 + 12V input Source Power Supply Design Guidelines UC864-E Hardware User Guide Battery Source Power Supply Design Guidelines UC864-E Hardware User Guide Thermal Design Guidelines Power Supply PCB layout Guidelines Antenna Requirements AntennaAntenna Installation Guidelines Operating Range Interface levels 1.8V Cmos Logic level specificationsAbsolute Maximum Ratings -Not Functional Operating Range Interface levelsReset signal Absolute Maximum Ratings Not Functional Serial PortsSignals of the UC864-E serial port are RS232 level translation UC864-E Hardware User Guide UC864-E Hardware User Guide 5V Uart level translation UC864-E Hardware User Guide Communication ports combinations USB PortSelection Audio Section OverviewGenerality DefinitionsInput lines microphone Electrical CharacteristicsEarMT Buffers Output lines speakerNot General Purpose I/OLogic level specifications Using the Alarm Output GPIO6 Using a Gpio Pad as InputUsing a Gpio Pad as Output Using the Buzzer Output GPIO7 LED status Device Status Indication of network service availabilityRTC Bypass out VAUX1 power outputOperating Range VAUX1 power supply Mounting UC864-E on your board USB Vbus Usbid Debug of the UC864-E in productionConformity Assessment Issues Safety Recommandations Revision Date Changes Document Change Log