Other Parts Discussed in Thread: LM7705, OPA2990
My Japanese customer has a question about OPA2170AIDCU. The question is below:
This op amp is used as a voltage follower for the buffer before and after the voltage dividing resistor in a product currently under development by our company. It is a circuit that converts 0 to 13 V analog input to 0 to 3.3 V by voltage division and connects it to the analog port of the microcomputer (R5F100EHANA # U0), but the voltage input to the analog port is differnet from the designed value. When the pull-down resistor 10kΩ is inserted into the amplifier output after voltage division of the above circuit, if the analog input voltage is 7V or more, the design values are met, and when the pull-down resistor 1kΩ is inserted, all the design values are met.
Why do pulldown resistors improved and smaller resistance values improved better, can you give us your view on possible causes and possibilities?
Circuit diagrams, measurement data, etc. are summarized in the attached file. Can you confirm it at the same time?