Manuals / Texas Instruments / Home Audio / Stereo Receiver

Texas Instruments DEM-DAI3793A manual LC Low-Pass Filter, Speaker Output Filter Configuration

Models: DEM-DAI3793A

1 101

Download 101 pages 11.29 Kb

Page 58

www.ti.com

Measurements for Dynamic Characteristics

5.4.3.1LC Low-Pass Filter

Daughter Card #2 provides an LC low-pass filter (LPF) to obtain a clean analog signal from the pulse-width modulated (PWM) output of the speaker output. This configuration is shown in Figure 5-7. Additionally, a snubber circuit is inserted into the signal line to achieve the best output power performance by suppressing ringing in the PWM pulse; however, a snubber circuit will have negligible effects in the end system.

SPOL

SnubberCircuit

SPOR

(1)

SPOLN

SPOLP

R5R6

330Ω 330Ω

C11C12

2.2∝F 2.2∝F

Note(1):SameconfigurationatSPORN/SPORP

LCLPF

L122∝H

L222∝H

C8C9

0.82∝F 0.82∝F

J3

J4

TP2

J3

TP1

fC =

−

Audio

Analyzer

Differential

Input

RL

8Ω

+

1

2 ⋅ π ⋅ LC ≈ 37.5[kHz]

Figure 5-7. Speaker Output Filter Configuration

58

Evaluation and Measurements

SBAU127 –July 2007

Submit Documentation Feedback

Image 58

Texas Instruments DEM-DAI3793A manual LC Low-Pass Filter, Speaker Output Filter Configuration

Contents

Users Guide Submit Documentation Feedback Contents 100 List of Figures Side List of Tables Submit Documentation Feedback About This Manual How to Use This Manual Information About Cautions and WarningsIf You Need Assistance FCC Warning Related Documentation From Texas InstrumentsAdditional Documentation TrademarksDescription Pin Assignments and Terminal FunctionsKey Features Introduction-PCM3793A/94AIntroduction-PCM3793A/94A Pin Assignments and Terminal Functions PCM3793A/94A Terminal FunctionsDEM-DAI3793A/3794A EVM System Diagram DEM-DAI3793A/3794A EVM DescriptionSBAU127 -July Getting Started Electrostatic Discharge Warning Unpacking the EVMDefault Configuration EVM ConfigurationMotherboard Daughter Card #2 DEM-TRVC/LPCSet-Up Guide Software Control and Operation Basic Operating Set-UpUser Interface Panel Power On/Off Sequence Module Function ControlsPower Up/Down HP COM/MONO HPCPower Up/Down Time ms Options PCM3793A/94A Resistor 1257dh RES40 Resistor Value ControlRamp Up Wave Form with Default Setting Default Setting RecordDigital Mute ATR Options Gain Control for ADC Input OptionsDigital Out Mute Control Options Playback Playback Function Menu TabHeadphone Gain Control Options Speaker Gain Control OptionsAuto Level Control Record Options Digital Attenuation ATP OptionsALC Automatic Level Control Output Options Signal ProcessingSource Options Tone Control Options3D Effect Options Click Apply to Filter 1 or Apply to Filter15. Notch Filter Characteristic Model De-Emphasis Filter Options DAC Oversampling Control OptionsZero Cross Control Options High-Pass Filter OptionsAnalog Path 18. Analog Path Function Menu TabAnalog Mixer Options Analog Input OptionsD2S Select Options Mic Boost OptionsPG5 Gain and PG6 Gain Options Audio Interface Setting 1 OptionsAudio Interface Setting 2 Options Audio InterfaceHP Short Detection, L-Ch HP Detection, R-Ch HP Detection OptionsHP COM Short Detection Options Speaker Short Detection, L-Ch Speaker Short Detection, R-Ch4 LC89052T DIR Digital Audio I/F Receiver Control Window Digital AmplifierRegister Setting History 24. Register Setting History WindowModifying a .csv File 25. Opening and Modifying a .csv FileRead function Register Direct AccessWrite function Switches and Connectors Daughter Card #2 DIR LC89052T and DIT DIT4096Overview Main Power Supply and RegulatorPower-Supply Terminals for PCM3793A Power-Supply Pins MotherboardAudio I/O I/F Controller MSP430, TUSB3410Daughter Card #1 PCM3793A Analog Input and Output-Daughter Card #1Analog Output Configuration Daughter Card #1 Analog Input and Output-Daughter Card #2 Daughter Card #2 DIR LC89052T and DIT DIT4096Audio Clock and Input Data Control Format-Daughter Card #2 Evaluation and Measurements Slave Mode With Audio Precision SYS-2722 Default Setting Slave Mode Configuration With SYS-2722Jumper Configuration for Slave Mode Default Master Mode with Audio Precision SYS-2722 Master Mode Configuration With SYS-2722Jumper Configuration for Master Mode Combined Master and Slave Mode Configuration with SYS-2722 Combined Master and Slave Modes With PSIA-2722Measurements for Dynamic Characteristics Jumper Configuration for Combined Master and Slave ModesD/A Line Output Parameters Digital-to-Analog D/A PerformanceΩ Headphone Output Inserted in Headphone Jack J6 A/D Line Input Parameters Speaker Output Power PerformanceAnalog-to-Digital A/D Performance Stereo Speaker Output ParametersSpeaker Output Filter Configuration LC Low-Pass Filter4.1 A/D Spectrum Amplitude Versus Frequency PerformanceResult BPZ Zero Data Input Result -60dB Input 4.2 D/A Spectrum 11. D/A Amplitude vs FrequencyConnection Diagram for Practical Applications PCM3793A/94AFilter Consideration for Speaker Output 16. Recommended Ferrite Bead Filter for Speaker OutputSchematic, PCB Layout, and Bill of Materials Schematics PCM3793A DEM-PCM3793RHB-A Connector Daughter Card #1PCM3793A DEM-PCM3793RHB-A Daughter Card #1 Printed Circuit Board Layout PCM3793A DEM-PCM3793RHB-A Board Layout-Silkscreen SidePCM3793A DEM-PCM3793RHB-A Board Layout-Component Side PCM3793A DEM-PCM3793RHB-A Board Layout-Inner Layer PCM3793A DEM-PCM3793RHB-A Board Layout-Inner Layer PCM3793A DEM-PCM3793RHB-A Board Layout-Solder Side Component List Bill of MaterialsSubmit Documentation Feedback Appendix a Reference .csv Files Table A-1. .csv FilesRelated Signal Flow Diagrams Figure A-1. Line Output and Headphone OutputFigure A-2. Headphone Output with Sound Effect Figure A-3. Cap-Less Headphone Output Figure A-4. Headphone Output with Line Input AIN2L/AIN2R 0dB AIN3L MUX1 AIN2L AIN1L D2S AIN1R MUX2 AIN3R AIN2R Figure A-7. Stereo Speaker Output Figure A-8. Mono Speaker Output Figure A-9. Speaker Output with Line Input AIN2L/AIN2R Figure A-10. Speaker Output with Mono Mic Input AIN1L, +20dB +20dB Figure A-12. Line Input AIN2L/AIN2R to Headphone Output Figure A-13. Mono Line Input AIN2L to Headphone Output Figure A-14. Mono Mic Input AIN1L, +20dB to Headphone Output +20dB Figure A-16. Mono Mic Input AIN1L, +20dB to Speaker Output Figure A-17. Line Input AIN3L/AIN3R Figure A-18. Mic Input AIN1L/AIN1R, +20dB Figure A-19. Mic Input AIN1L/AIN1R, +20dB with ALC Figure A-20. Mono Mic Input AIN1L, +20dB Figure A-21. Mono Mic Input AIN1L, +20dB with ALC Figure A-22. Mono Diff Mic Input AIN1L/AIN1R, +20dB Figure A-23. Mono Diff Mic Input AIN1L/AIN1R, +20dB with ALC Figure A-24. Slave Mode Operation Interfacing to DSPsRegister Control with DSP Interface Table A-2. Recommended Power-On Sequence for PCM3793APackage Information Evaluation BOARD/KIT Important Notice FCC WarningImportant Notice