DA output voltage accuracy cannot be achieved

有星星的天空

DA output voltage accuracy cannot be achieved [Copy link]

The chip used is LTC2668-12, the output voltage range is +-10V, it is divided into 1024 parts, in theory, any gray value from 0 to 1023 corresponds to a different voltage value, but when the gray value is greater than 200, there will be several gray values corresponding to the same voltage value, but when it is less than 200, one gray value corresponds to one voltage value, why is this?

bigbat

I think the problem is more complicated

1. Use a more precise resistor without connecting a load, and then test whether it is normal. If it is normal, it is a circuit problem. If it is a circuit problem, you need to add a voltage follower circuit.

2. If the problem persists after adding the follower circuit, analyze whether the circuit is linear or not. If so, make corrections.

chunyang

There is not enough information to judge. It may be a software problem, such as an error when writing data greater than a certain value. It may also be a hardware problem, which depends on the specific circuit.

Special reminder: If you want to get timely and effective help, first learn to describe the problem correctly and completely.

Gen_X

Generally, DA accuracy is mainly due to the peripheral circuits not being able to achieve it. The accuracy of the op amp, power supply, proportional resistor, and the location of the power supply and ground all have an impact on the output result. Under normal circumstances, the voltage output accuracy is still higher. If it is current output, the circuit is more particular.

There are many typical analog circuits with a resolution exceeding 1024, but it is not easy to meet the accuracy requirements.