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I am asking some basic questions here. I have a sensor whose voltage specs are 0-5V and I have to interface this with my TI MSP430's ADC, whose voltage Vcc is 3.3V . For this I have to convert the level of the output of the sensor.

1) Can I accomplish this using a simple potential divider, that is, I use two appropriate resistors in series, and then tap the drop across one of them and feed that to the ADC?

2)If yes, then are there some additional things that I should look into?

3)If no, can someone suggest a suitable alternative?

Gautham
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1 Answers1

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  • 1) Can I accomplish this using a simple potential divider, that is, I use two appropriate resistors in series, and then tap the drop across one of them and feed that to the ADC?

    Yes, using a voltage divider is a good solution.

  • 2)If yes, then are there some additional things that I should look into?

    Find the datasheet of your sensor an find out if it has a minimum load requirement and find its maximum load. Make sure your resistive divider is well below the maximum load of the sensor. Also take tolerances (and temperature dependency) of the resistors in account and how they reflect on the measured value. Preferably make sure the voltage cannot get higher/lower than the power rails of the microcontroller by using (Schottky) clipping diodes.

schematic

simulate this circuit – Schematic created using CircuitLab

  • 3)If no, can someone suggest a suitable alternative?

    Counteless ways to solve this, but a resistive divider is simplest.

jippie
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