Provides 24-bit ADC chip

QWE4562009

Provides 24-bit ADC chip [Copy link]

 

Provide a high-precision external reference for a 24-bit ADC chip. The higher the accuracy, the better. What models are recommended? The microcontroller is powered by 3.3V

qwqwqw2088

Many 24-bit ADC chips should have their own benchmarks.
It's a bit too much to add an extra benchmark.

qwqwqw2088

TI's benchmark is expensive.

REF3433-EP Enhanced Product, 3.3V, Low Drift, Low Power, Small Size Series Voltage Reference

不谏

TI's REF3025 is pretty good

littleshrimp

LTC6655

bigbat

According to my experience, this kind of 24-bit ADC usually measures a relatively high input voltage, some of which can even reach 20V, so the reference does not need to be very precise, but it needs to be very stable and have good temperature drift control, such as the measurement of electronic weighing.

If you are a circuit that requires precise measurement, I don't know about this.

It is recommended to first look at the input voltage range of the ADC. If it is higher, such as 15V, then increase the input voltage and keep it similar to the benchmark.

I have been working in the instrument industry for many years.

QWE4562009

qwqwqw2088 posted on 2023-7-31 21:26 Many 24-bit ADC chips should have their own benchmarks, and the additional benchmarks are a bit much

Not enough precision

QWE4562009

qwqwqw2088 posted on 2023-7-31 21:26 TI's reference is expensive REF3433-EP enhanced product, 3.3V, low drift, low power, small size series voltage reference

What is the accuracy of this

QWE4562009

Bu Jian posted on 2023-8-1 09:19 TI's REF3025 is pretty good

How many V and how many digits of accuracy?

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littleshrimp published on 2023-8-1 09:32 LTC6655

I can't afford the Sprinter. It's too expensive.

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bigbat posted on 2023-8-1 09:32 According to my experience, this kind of 24-bit ADC usually measures a relatively high input voltage, some can even reach the range of 20V, so the benchmark does not need to be very precise...

Hello-----but it needs very stable and good temperature drift control. How to control this? Please teach me

bigbat

QWE4562009 posted on 2023-8-1 18:35 Hello-----but it requires very stable and good temperature drift control. How to control this? Please teach me

This is a big problem. Generally speaking, it is related to the design of the circuit and the selection of components.

Stability: The power of the reference circuit should be as large as possible. For example, when using TL431, the resistance should be reduced as much as possible when the resistance meets the requirements. If that still does not work, add a voltage stabilization circuit.

Temperature drift: There are many solutions in this regard, such as adding temperature compensation to the circuit and using components with good thermal stability.

bigbat

QWE4562009 posted on 2023-8-1 18:35 Hello-----but it requires very stable and good temperature drift control. How to control this? Please teach me

It should be noted that all components should be of high precision and good thermal stability, and usually need to be combined with related circuits.

bigbat

If the voltage of the ADC is higher than that of the microcontroller, the circuit will not work and will damage the microcontroller. You can use a level conversion chip or circuit. I usually use a high-speed optocoupler isolation circuit. I have made a 24-bit ADC circuit with a 15V input.

QWE4562009

bigbat posted on 2023-8-1 18:52 If the voltage of the ADC is higher than the circuit of the microcontroller, it will not work and will also damage the microcontroller. Just use a level conversion chip or circuit. I usually...

Hello, please post the picture so I can learn from it.