SaM ~ Real World Example of a Classical Band Gap Based Temperature Sensor

Remeber:

• This is linear, but only if the thermocouple is linear.
• Basic TMP35 sensor: $\alpha =41\frac{\mu \text{V}}{\text{°C}}$. (used for compensation)
• Using this structure (thanks to both sensor and thermocouple) we go from the original sensitivity which is $41$ micro volt per degree, to a larger sensitivity which is $10$ millivolt per degree.

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• So this is an example and it is a complete instrumentation amplifier and thermocouple called junction compensator on a monolithic chip.
• You only have to add the thermocouple, which is the only external part here, everything else is in the chip.
• So it becomes a cold junction, so there is the need for a isothermal block, since you need to measure the temperature of this junction here, and this is performed by means of this internal voltage $V_R$, “output” of the TMP35 (actually the output is a resistance).
• At the end we have also this amplifier here which amplifies the voltage and we go from the original sensitivity which is $41$ micro volt per degree, to a larger sensitivity which is $10$ millivolt per degree.NOT_SURE_ABOUT_THIS (The increase in sensitivity should be mostly due to the termocouple)
• This is linear, but only if the thermocouple is linear.