Analog and audio

Hello; I have the electronic circut card including ST microelectronics IC component. On the top of component, 256D is written. SOIC8 package I couldnt find any tecnical information on the internet. According to electronic circuit, it seems an OPAMP not serial EEPROM or memory device. Would you please help me what kind of IC is 256D? 

MC33078:what's the meaning about MZ,GZ,EZ markcode on the top of IC?if it means different places of production? We find that the MC33078 with different markcode influences the tone colour we listen.The MC33078 is used in our  KTV PROCESSOR

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Hello, I have simulated the spice model of LM2904 in LTSPICE for the input voltages as shown in figure , as per the theoretical calculation output voltage will saturate to supply voltage VCC=12 V , but from simulation results output voltage getting 10.7 Volts.Kindly suggest me the solution for the same ASAP .

If i want to run TDA7498e as a monoblock, do i then need the capacitors on pin 32 / 33..?Both pins are tiet to ground in mono.

Hi, I have an active subwoofer with a burned chip on it. Unfortunately the model number is unreadable in the last number/s. The reading says TDA729* and under it CZ041936. Is there a way to get the correct model? I tried to contact the manufacturer of the speaker with no success. Thanks in advance

Basically we are thinking to use sensor tile as a voice recognition module and for that we need some info regarding module train process how it will easy for user to train any customize voice ?And this voice recognition module able to distinguish two or more than two people if they are given the same voice command at the same time but it recognize only one whose voice has been trained.?Thanks

The ic is damaged, came from Epson Proyector S41+.It is an integrated audio circuit, the integrated circuit is heated and there is no audio coming from it, it is a surface welding circuit. I need the datasheet or know the audio input and output pins to adapt one. Thank you.

Hey guys,I am using a STM32 F411E DISCO board and downloaded ST FP AUD_SMARTMIC1 library to learn audio feedback suppression caused by a mic and a PA ampliflier nearby. In the library C files given in the projects folder of FP AUD_SMARTMIC1, they are coded keeping a NUCLEO- F446RE, CCA01M1 board (for audio terminal, interfacing with speaker/PC) and CCA02M1 board (for microphone plugging), in mind. The F411E DISCO board has an embedded mic(and I am going to use it), a port to connect to external amplifiers and a USB port to transfer audio data to PC, all in one board. So I won't be needing the expansions board for my purpose.I need to tweak the SMARTMIC1 library according to my F411E DISCO board, so I may need to make some changes in "usbd_audio_cdc_interface","STCmdP_interpreter" and maybe "usbd_audio_if" C library files and other non-mentioned library files too.I don't know how to start and where to start to edit the SMARTMIC1 library according to the F411E DISCO board. I tried to sea

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I tried changing the audio sample rate from 16K (which is working) to 22k and 44k - both without success. I just changed the #define AUDIO_SAMPLING_FREQUENCY but the generated WAV-Files which are saved on µSD-Card are not working properly and the length is not correct. Any hints on how to change the sample rate properly to more than 16 k ?

A company in China has designed a new amplifier for one of my biggest clients.However, when they sent us samples it is powered by the STA326 chip.As part of my due diligence I realise this chip is marked "obsolete'.When I asked the manufacturer about this they said it's actually an STA329 chip, but for some reason is still engraved with STA326.I find that highly doubtful!Anyway, I cannot find any information about the SAT329 except a news article from several years ago. Is there really such a chip as STA329?, Is it in production?Is it suitable for new designs?Would early "STA329" chips really be marked as "STA326"?

Please let me know BD911 ROHS2 plan.Or send me ROHS 2 company statement.​

I have 20 radio , 19 radio is fine but one of the radio TDA7391PD (audio pa) pin 16,17,18 , 19 burned

Hello, I have found an implementation of the Goertzel algorithm that contains code that I don't understand. And more specifically the pre-calculation of coefficients. :pensive_face: At the top of the code there is :#define DTMF_697Hz 27980 #define DTMF_770Hz 26956 #define DTMF_852Hz 25701 #define DTMF_941Hz 24219These defines are used inside the goertzel calculation like such :for (i = 0; i < N; i++) { v0 = ((cos_fact * v1) >> 14) - v2 + *x; x++; v2 = v1; v1 = v0; }x is my buffer.v0, v1 and v2 are long intcos_fact is the one of defines I showed above and passed as a function parameter.My questions would be: What do these define correspond to? How to pre-calculate them for other frequencies? Is it normal that the values are so far apart?Thank you ! :smiling_face_with_smiling_eyes: ps: This code is part of ampm_open_lib and my goal would be to use it for detecting other frequencies than DTMFs tones.

Hello everyone,we currently devolping an Class D amplifier with the sta309a as DSP and TAS5624A from TI for amplification.We face a issue with random levels of noise appearing after power up sequence.This may be an issue of wrong configuration during the start. I hope to get any hints what could be wrong...Here are some more details about the power up sequence:sta309a recieves I2S with MCLK=24576Enable power and Reset Pin of sta309aEnable binary PWM-output mode as DDX damped ternary mode is not supported by TI-chipWrite a set of coefficents and configure all biquads etc.Configure correct sample-rate and set volume.Finally enable the TAS5624A Normal Noise level:High Noise Level after boot up:

When I am changing the number of channels to 1 channel.it is recognized by the windows driver, but the"advanced" TAB is disappear (unlike 2 channels configuration). Did someone faced with this kind problem? Do I missedsomething? of course, audacity do not allow to record and I receive this message:" error while opening sound device"

I have an integrated one of an ultrasonic washing machine.This when measuring its frequency oscillates in 80kHz, but after a few minutes it begins to decrease the frequency and increase uncontrollably, so I have decided to change it.the question is that where the model should appear is torn and can not be seen, but below shows this information.S "Tear" A (only the letter "S" is displayed at the beginning and the letter "A" at the end)V6 FG675CHN99614I will attach an image.I hope you can help me.Thank you.

Good day!I want to use STA309A.I want to signal MCLK (XTI) 256*Fs, bicki to signal 64*Fs.What frequency of PWM will I get, 384 kHz or 256 kHz?Real exampleFs = 32 kHzMCLK (XTI) = 256 * Fs = 8192 kHzBICKI = 64 * Fs = 2048 kHzWhat is the frequency of the PWM output work?I need a fixed frequency of 384 kHz.Can STA309A at a fixed frequency of MCLK(XTI) 256 * Fs to give out a PWM with a frequency of 384 kHz?Thanks.With respect, Valery.

Hello, hopefully this is the right place to post this.I am trying to use the Biquad Design Tool (v1.0.0.0) that is described in the Birquad Library UM1625 manual as part of the X-CUBE_AUDIO firmware package. I'm trying to generate a simple bandpass filter using the "Free Filter" design. The "ex_example.txt" generates a filter correctly at 48000 (Hz) sample rate, but I am unable to create my own.I set the Sampling Rate to 16000 (Hz) and created a .txt file with the following lines in it:0    -15100    -13300    -31000    02400    03000    -34000   -138000   -15I would expect this to generate a filter, but in the terminal window of the program it gives an error "Attempted to access idx(1); index out of bounds because numel(idx)=0. [7 more lines of traceback...] Error while evaluating uicontrol Callback"Does anyone know what is going on or workar

Please share the recommended schematic for STA321MPL1.

How are you?I would like to test an ultrasound pulser IC evaluation board (STEVAL-IME012V1) on Windows 10 PC. I installed a test software (STSW-IME011) to configure waveforms (frequency and number of pulses) for the evaluation board. However, I have not connected the evaluation board to the Windows 10 PC. The PC has not shown a suitable COM port (USB- 5 pin connection) yet. Would you please show me how to find the evaluation board on the Windows 10 PC?Actually, I connected only with the 5-pin USB port to the PC. Should I connect power lines to the evaluation board?Thank your for your help.

Battery Fuel Gauge via STM32.Whether provide test code?​​