Telit Wireless Solutions UC864 manual Electrical Characteristics, Input lines microphone

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UC864-E Hardware User Guide

1vv0300766a Rev.1 - 31/01/08

10.4 Electrical Characteristics

10.4.1 Input lines (microphone)

The two transmit blocks are fully equivalent, connected in Differential mode

Line coupling	AC (*)
Line type	Balanced
Coupling capacitor	≥ 100nF
Differential input resistance	20kΩ
Differential input voltage	≤ 1,03Vpp @ HSMicG=0dB

Table 1. “Mic_MT” 1st differential microphone path

Line coupling	AC (*)
Line type	Balanced
Coupling capacitor	≥ 100nF
Differential input resistance	20kΩ
Differential input voltage	≤ 1,03Vpp @ HFMicG=0dB

Table 2. “Mic_HF” 2nd differential microphone path

Due to the fact that particular OEM applications need a single line connection, a Single Ended configuration could be implemented, but halving the useful microphone signal.

In both cases the OEM circuitries shall be carefully designed to reduce the common mode noise typically generated on the ground plane.

WARNING

In the previous tables, the line coupling definition AC (*) means that:

the signals from microphone must be connected to the input lines of the UC864-E through CAPACITORS, not less than 100nF

Not respecting this constraint, the input stage will be damaged!

Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved

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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 a Gpio Pad as Input Using a Gpio Pad as OutputUsing the Alarm Output GPIO6 Using the Buzzer Output GPIO7 LED status Device Status Indication of network service availabilityVAUX1 power output Operating Range VAUX1 power supplyRTC Bypass out 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