Description

Upgraded version of ADS1256 24-bit ADC 8-channel AD module high-precision ADC data acquisition

An engineer saw a comment saying, “The accuracy is fine, but the channel is mislabeled. Channel 0 on the table is actually channel 1. This mistake wasted a lot of time.”

Actually, the buyer made a mistake. The channel is not mislabeled. Below is the engineer’s explanation.

The engineer explained that when a multi-channel ADC continuously acquires data, the current AD value is the AD value of the previous channel. This can be done by using variable transfer to match the channel number. This situation should be noted by beginners or those who have not used multi-channel ADCs.

Download: http://pan.baidu.com/s/1bNSiVO

What is most important for a high-precision ADC? In addition to high resolution, a high-quality voltage reference is essential. This board uses the Analog Devices ADR03 as the voltage reference. The ADR03 features the following:
1. A temperature coefficient of less than 3ppm/°C. This determines the impact of temperature changes on the ADC data. 3ppm/°C means that every degree change causes a change of 0.3 parts per million in the voltage reference. Therefore, a high-quality voltage reference is crucial!
2. Initialization accuracy less than ±0.1% (the error between the output voltage and the reference value) determines the consistency of a batch of products.
3. Noise less than 10uVp-p. The noise of the voltage reference output also directly affects ADC accuracy. Typical noise is between 0.1Hz and 10Hz. Adding a 0.1-10Hz low-pass filter effectively reduces low-frequency noise.