Two-channel Analog-to-Digital converter board with USB interface


Posted on Feb 4, 2014

build an interface board to connect some scientific equipment (for me, a pair of photovoltaic tubes) to a personal computer to acquire measurements results. Signal properties were following: two channels with a common ground, 1 second of acquisition time, max 10V signal level. Desired digitizing properties were about 1000 samples per acquisition, 10 bit depth. The most attractive


Two-channel Analog-to-Digital converter board with USB interface
Click here to download the full size of the above Circuit.

and cheap solution is to use a PC sound card as an ADC converter. However, most of laptop computers have only mono low-level microphone input onboard. After a careful research, a Texas Instruments PCM2900 chip [1] was chosen as a proper converter (fig. 1). It has a stereo I/O (only input is used in this project), USB interface and MS Windows drivers already shipped with an OS. A reference board design from TI was used (fig. 2). One can easily found it in the data sheet [2]. Output circuits were removed, and proper capacitors selected. C9 and C10 capacitors were removed as input signal have zero frequency (DC). Instead, a couple of potentiometers (5K and 10K) were placed to do fine board tuning. After an assembly has been finished, the board was plugged onto my PC (Windows XP): Check the "USB HID", "USB Audio device" and "USB Composite device". Also I had to specify a new source for sound recording.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Flashing Led Controller
    Audio Mini FM Receiver
    TV Transmitter circuit diagram (VHF)
    rust
    USB Charge PCB
    Connecting an IR Sensor
    High voltage ohmmeters
    Armstrong Oscillator
    Incandescent Yeonsu electronic controller 3



    Top