Telit Wireless Solutions GE863-PY, GE863-QUAD manual Hands-Free Earphone Low Power Design

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GE863-QUAD

GE863-PY

1vv0300715 Rev. 1 - 19/09/06

The resulting gain and high pass cut can be obtained with the formula:

Gain = RR32

freq. = 1 [Hz] 2π * R3* C4

And an example of internal Ear amplifier could be :

+12dB

GE863-QUAD / PY

Some amplifier require a low impedance load at high frequency in order to avoid auto oscillation, this can be made with a capacitor (100nF) in series with a resistor (15Ω).

When designing your application, remember to provide an adequate bypass capacitor to the amplifier and place it close to the power input pin of the IC, keeping the traces as short as possible.

8.5 Hands-Free Earphone (Low Power) Design

The same design considerations made for the handset are valid for the hands-free earphone.

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Contents GE863-QUAD GE863-PY Hardware User Guide Contents 10.1 10.210.3 10.412.1 13.113.2 This document is relating to the following products Overview GE863 module connections PIN-OUTPin Signal Function Internal Type Pull up Pin Signal Function Internal Type Pins Layout Hardware Commands Turning on the GE863-QUAD/PYTurning OFF the GE863-QUAD/PY Turning off of the device can be done in two waysHardware Unconditional Reboot Hardware shutdownGE863-QUAD Power Supply 1Power Supply RequirementsGE863-QUAD/PY power requirements are 2General Design Rules Electrical design Guidelines1.2 + 12V input Source Power Supply Design Guidelines An example of linear regulator with 5V input isBattery Source Power Supply Design Guidelines An example of switching regulator with 12V input isBattery Charge control Circuitry Design Guidelines Thermal Design Guidelines Power Supply PCB layout Guidelines Antenna GSM Antenna RequirementsGSM Antenna installation Guidelines Serial PortsGSM Antenna PCB line Guidelines Absolute Maximum Ratings -Not Functional Parameter Min Max Level Min MaxSignals in the Uart connector on the EVK are Number Pad Number17-28-36 Ground 45-48-50-56 Clear to Send Output from the GE863-QUAD/PY thatIt is available on the following pins 2MODEM Serial Port 2 Python Debug3RS232 level translation An example of level translation circuitry of this kind is 5V Uart level translation GE863-QUAD Audio Section Overview GM863-GPS Microphone Paths Characteristic and Requirements Echo canceller type HandsetEcho canceller type Car kit hands-free + 20dBThat means You can set GA= +20dB to use standard resistor valuesTIP environment consideration General Design Rules Other considerationsMicrophone Biasing Balanced Microphone BiasingUnbalanced Microphone Biasing GE863-QUAD Microphone Buffering Buffered Balanced MicSample circuit can be Gain = RR604605 = RR607606 Buffer gain is given by the formulaBuffered Unbalanced Single Ended Microphone Freq . = 2π * R719* C726 2π * R711* C727 Buffer bandwidth at -3dB shall be 4KHzGE863-QUAD Output Lines Speaker Short descriptionOutput Lines Characteristics SW volume level step Number of SW volume stepsNoise Filtering Handset Earphone Design Hands-Free Earphone Low Power Design An example of internal Ear amplifier could beCar Kit Speakerphone Design Evaluation Kit for Telit Modules EVK2 Short Description2 EVK2 Audio Lines Characteristics @ 350mWData Integrity ESDSchematic SIM SupplyLayout Using a Gpio Pad as Input Using a Gpio Pad as OutputGeneral Purpose I/O 10.3Using the Alarm Output GPIO6 Using the Buzzer Output GPIO7DAC and ADC section 11.1DAC ConverterDescription Min Max UnitsAn AT command is available to use the DAC function Command is AT#DAC=enable,valueEnabling DAC Low Pass Filter ExampleUsing ADC Converter Input Voltage range AD conversion Bits Resolution11.2ADC Converter Camera 12.1Transchip CameraType Sensitivity LuxCamera Interface Connectors Camera Physical Detail & Connector Camera Socket Connector Camera Board Module Main Block Diagram for supported cameras Schematic Diagrams for supported camera Camera setting shown here are the defaults ones Example usage script for cameraTaking an reading a photo 13.2Module Finishing & Dimensions Mounting the GE863-QUAD / PY on the Application Board13.1General Surface finishing Ni/Au for all test pads Lead-free AlloyRecommended foot print for the application Debug of the GE863 in Production StencilPCB pad Design Solder paste 13.2.6 GE863-QUAD / PY Solder Reflow Following is the recommended solder reflow profileGE863-QUAD Packing System Section A-AModules orientation on tray Moisture Sensibility Conformity Assessment Issues Safety Recommandations Document Change Log Revision Date Changes21/02/06 19/09/06