Electronics > Beginners
How to make an analog circuit to proportionally scale a sensor output voltage?
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HwAoRrDk:

--- Quote from: mikerj on July 05, 2019, 08:57:15 am ---That quite a nice part, but I don't think it provides any over-voltage protection and it's voltage operating range is lower than the MCP6001.  I'd think I'd choose an op-amp with a wider supply range and then use a TVS and maybe a polyfuse for protection.  You'll want to add some resistance on the op-amp output to limit current if that is connected to something bad, it can go before the feedback resistor so any voltage drop is compensated.

--- End quote ---

It does provide over-voltage protection: "An internal reverse-voltage detection comparator disables the power-switch if the output voltage is higher than the input voltage to protect devices on the input side of the switch." I found it because it is one of the few USB-focused high-side switches that actually does that; most only give reverse-current protection when off and don't prevent the output going higher than input.

I'm not concerned with over-voltage on the 5V reference supply feeding this circuit. The existing sensor is actually contained within the device's enclosure (have to run a hose to it, which is inconvenient, thus part of my motivation for replacing it), and this add-on circuitry, while 'in-line', would live there too, so there is no possibility of wire shorts, etc. between the device and it. And if the device's 5V rail goes over-voltage, then the device itself has probably had the magic smoke escape, so the continued functionality of this op-amp circuitry becomes immaterial! :) With a new external remote pressure sensor however, there becomes a risk of incorrect connection, shorts, etc. on wiring so I think it is indeed right to give attention to some protection, but only that side.

Oh, also, the device itself already has some series resistance on the sensor input signal (and hence to be on op-amp's output): a 1K/470pF low-pass filter. Not much, but it's something.
GerryR:
Just because I'm nosy, and after all this, and if it's not a big secret, what is the application??  :-//   Just very Curious.
HighVoltage:
Some of the modern automotive pressure sensors are no longer analog.
The new types are digital and can be programmed.
And they run at about 1000 Hz update rate.
Many of them even have a temperature compensation.

 
max_torque:

--- Quote from: HighVoltage on July 06, 2019, 11:20:16 am ---Some of the modern automotive pressure sensors are no longer analog.
The new types are digital and can be programmed.
And they run at about 1000 Hz update rate.
Many of them even have a temperature compensation.

--- End quote ---

https://en.wikipedia.org/wiki/SENT_(protocol)

JustMeHere:
Micro with ADC and DAC. Then let the micro do the math.
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