LMV1089RLEVAL National Semiconductor, LMV1089RLEVAL Datasheet

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... The LMV1089 demo board offers the means for easy evalu- ation of the LMV1089 Dual input, Far Field Noise Suppression (FFNS) Microphone Amplifier with Automatic gain Ability and Differential Outputs. This board has the LMV1089 mounted © 2009 National Semiconductor Corporation National Semiconductor Application Note 1832 Nisha Patel June 16, 2009 • ...

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General Description The LMV1089 is a fully analog dual input, differential output, microphone array amplifier designed to reduce background acoustic noise, while delivering superb speech clarity in voice communications applications. The LMV1089 incorporates calibration circuitry which may be initiated by ...

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LMV1089 Demo Board Features With the LMV1089 demo board, evaluation of the noise sup- pression function of the LMV1089 is very convenient. This board makes it easier to measure most of the characteristics of the LMV1089 that can be found ...

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Power Supply of the LMV1089VY Demo Board The LMV1089VY demo board provides three (3) possible sources for the power supply. The first one is using the ex- ternal supply via header J12 for V DD pin can get its supply ...

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Adjustable Gain The LMV1089 has two gain stages where the gain can be adjusted to meet the requirements for the application . There is a pre amplifier and a post amplifier gain that can be varied independent of each other ...

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The On Board Compatible Interface The Compatible Interface that is available on the LMV1089 demoboard is located at the header J20 with an indication ' I2C' printed on the PCB (see Figure 6). The ...

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LMV1089 Control Demo Software Together with the LMV1089 demo board, there is a software package available that can assist in evaluation, programming, and testing of the LMV1089 chip via the I software is operated via the graphical user interface as ...

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Measuring Characteristics of the LMV1089 Important: Whenever the LMV1089 part calibration data is stored into the EEPROM, some parameters like Gain will differ from the measured data in the datasheet. This is due to the nature of the calibration system ...

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Unprocessed_Output Pins The individual stereo output signal of the two microphone channels MIC1 and MIC2 are available at the corresponding Connecting Microphones to the LMV1089 Demoboard The demoboard can be used to connect a set of two micro- phones to ...

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For a optimal performance of the Far Field Noise Reduction system it is important to find the correct placement of the mi- crophones. In many applications the microphones are placed next to each other with a distance of 1.5cm to ...

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FIGURE 12. Broadside Array (WRONG) FIGURE 13. End fire Array (CORRECT) 11 30060610 30060611 www.national.com ...

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Automatic Calibrating of a System Containing the LMV1089 The full automatic calibration should only be required once, when the product containing the LMV1089 has completed manufacture, and prior to application packaging. The product containing the LMV1089 will be calibrated to ...

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Note: When the operated, make sure that register 'R' (address 0x12) bit 0 is '0' before operating the CAL pin (default value for this bit). When this bit is set '1' the calibration engine of the ...

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Performing a Three Tone Calibration In a system with two microphones in an enclosure there will always be a difference in the transfer function in both gain and frequency response. The LMV1089 has the capability to per- form an automatic ...

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TABLE 5. Automatic Calibration Timing Parameters Symbol t Calibration Start Tone 1 ST1 t Calibration End Tone 1 ET1 t Calibration Start Tone 2 ST2 t Calibration End Tone 2 ET2 t Calibration Start Tone 3 ST3 t Calibration End ...

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Automatic Calibration Setup A calibration test setup consists of a test room (acoustical box) with a loudspeaker (acoustical source) driven with the test tone (e.g. the sequence from Creating the Three Tone Sequence with an AWG). The test setup is ...

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Description of Headers and Connectors of the LMV1089 Demoboard The LMV1089 demoboard provides many headers and con- nectors for connecting test equipment and controlling the settings of the part. The function that is controlled by the Connector and Header Functions ...

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Schematic for the LMV1089RL www.national.com 18 30060655 ...

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Demo Board Layout for the LMV1089RL FIGURE 21. Silk Screen FIGURE 22. Top Layer 19 30060650 30060651 www.national.com ...

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FIGURE 23. Top Inner Layer FIGURE 24. Bottom Inner Layer 20 30060652 30060653 ...

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FIGURE 25. Bottom Layer 21 30060654 www.national.com ...

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Bill of Materials for the LMV1089RL Demoboard Designator Component BT1 Bat holder CR1220 C2, C6, C15 Capacitor Ceramic C3, C4, C7, C8, C9 Capacitor Ceramic C5, C14 Capacitor Ceramic C5a, C14a Capacitor Ceramic C10, C13 Capacitor Ceramic C11 Capacitor Ceramic ...

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Connector and Header Functions for the LMV1089VY Demoboard Header/ Indication/Function Connector J1 (M1_UNP) Unprocessed audio output for microphone channel 1 J2 (M2_UNP) Unprocessed audio output for microphone channel 2 J3 (GA0) Default input gain setting bit 0 J4 (GA1) Default ...

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Schematic for the LMV1089VY www.national.com 24 ...

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Demo Board Layout for the LMV1089VY FIGURE 26. Top Silkscreen FIGURE 27. Top Layer 25 30060617 30060616 www.national.com ...

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FIGURE 28. Layer 2 FIGURE 29. Layer 3 26 30060614 30060615 ...

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FIGURE 30. Bottom Layer 27 30060613 www.national.com ...

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Bill of Materials for the LMV1089VY Demoboard Designator Part Number 551600279-001 U1 LMV1089VY C6, C15,16 C0603C105K4PAC C2 C0603C103K5RACTU C3, C4, C7, C8, C9 C0603C474K4RAC C5, C14 No Load C5a, C14a 06031C102KAT2A C10, C13 0603YC104KAT2A C11 No Load C12 TAJC107K010R R1, ...

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Notes 29 www.national.com ...

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