Unity Gain Buffer

I’m working with an analog sensor, and it says “when measuring [the output] directly,always use a unity gain buffer”. Does the argon have these onboard the analog inputs, or do I need to supply one externally?

@adam.rob.carter, usually a unity gain buffer is used to manage the impedance of the sensor or the ADC input of the MCU. The Argon does not have a unity gain buffer onboard. This is simply an op-amp wired for a gain of 1.

Can you provide a link to your sensor so we can look at its output characteristics?

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thanks for quick reply. The sensor is this gas sensor (the Vref and Vtemp outputs). The datasheet says

High impedance output requires a buffer to connect to any measurement device.

@adam.rob.carter the impedance warning only seems to apply to the Vref and Vtemp outputs. If you don’t need these, it looks like you can use the Vgas output directly.

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Yeah I got that, but what if I do?

@adam.rob.carter, the TI LM358 dual or LM324 quad op-amps are single supply devices which can be powered with 3.3v and used as unity gain amps.

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