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Discrete Analogue to Digital converter

Knighthawk_140

Hello.

I have made a 14bit single slope adc

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  • That sounds cool. Can you post a picture of it or a schematic or do you have a question about it?

  • in reply to dougw

    I have a video up on youtube of this working, it is based on a ramp counter, constant current linear ramp with comparator. I used an STC89C52 running at 20Mhz in 6T mode, this is based on the old 8051 microcontroller. With 20x4 LCD

  • in reply to Knighthawk_140

    We need a schematic - it's like home work - you only get marks if we can see your workings out  Relaxed

    For an A++ grade - try making it logarithmic !

    MK

  • in reply to Knighthawk_140

    Good Morning on this lovely Sunday, here is my ADC ramp in glorious 4K

  • in reply to michaelkellett

    This was just a diy build in my flat at weekends and evenings, I don't have an environmental chamber in my front room, i was seeing if it was possible to get a 14bit adc stable and fairly linear. If you analyse my video below you will see what I have achieved 

  • in reply to Knighthawk_140

    A challenge would need a more detailed spec:

    • Integral non linearity
    • Differential non linearity
    • Noise
    • Temperature drift
    • Sampling rate
    • Gain error/drift
    • Offset
    • Calibration interval

    It's quite acceptable for any of these parameters to be unspecified but if you don't pin down some of them it's not much of a challenge.

    For example - in your design schematic the current source is unlikely to be very linear (see TI document SYLT768.pdf).

    Too busy right now to have a go but if I do I'll tell you when my 10 days start Slight smile

    MK

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  • in reply to Knighthawk_140

    A challenge would need a more detailed spec:

    • Integral non linearity
    • Differential non linearity
    • Noise
    • Temperature drift
    • Sampling rate
    • Gain error/drift
    • Offset
    • Calibration interval

    It's quite acceptable for any of these parameters to be unspecified but if you don't pin down some of them it's not much of a challenge.

    For example - in your design schematic the current source is unlikely to be very linear (see TI document SYLT768.pdf).

    Too busy right now to have a go but if I do I'll tell you when my 10 days start Slight smile

    MK

Children
  • in reply to Knighthawk_140

    Good Morning on this lovely Sunday, here is my ADC ramp in glorious 4K

  • in reply to michaelkellett

    This was just a diy build in my flat at weekends and evenings, I don't have an environmental chamber in my front room, i was seeing if it was possible to get a 14bit adc stable and fairly linear. If you analyse my video below you will see what I have achieved