Start a new topic

Replacement of the operational amplifier LM358W in the CP (Control Pilot)

Hello! I collect OpenEvse Controller through data from GitHub (Eagle). The goal is personal experiments. The problem is the following: on the circuit OpenEVSE_PLUS_v4 in the control circuit of the pilot signal is the operational amplifier LM358W. The datasheet of this component indicates a service temperature of 0 ° C ~ 70 ° C, this is not suitable for me, because I will use charging in cold conditions (-25 -30 ° C). For cold conditions, there are operational amplifiers LM258W and LM158W (down to -55 ° C). I unfortunately did not find such operational amplifiers in the stores. Found one LM258DT, without the letter W (in the datasheet the temperature is set to -40). The question is - is this op-amp suitable for the stable operation of the charging station? If not, is it possible to help in finding a reliable operational amplifier for these purposes in this online store? https://lcsc.com/products/Low-Power-OpAmps_602.html. I will be very happy with any help, thanks for contributing to the green future!


The LM358W requires the enclosure temperature to be between 0 ° C ~ 70 ° C. The power supply and other electronic circuits in the enclosure will keep the temperature significantly warmer than the outside air temperature.  


1 person likes this

The pilot requires a OpAmp that can handle +-12V, so a JFET or rail-to-rail is suitable. I has been many years since I have tested anything other than the LF353. 


From your page, it looks like this one may work. https://lcsc.com/product-detail/Low-Power-OpAmps_TI_TL032IDRG4_TL032IDRG4_C47930.html 

I do not have any experience with that part, but it looks okay based on the general specifications.


Here is an alternate design that uses a DG419 analog switcher. https://www.barbouri.com/2017/03/10/diy-open-evse-v4-23/


1 person likes this

Chris, thank you for the answer! Unfortunately I can not find the usual LM358W in the store. So I decided to look from scratch and still pick up with working temperature to -40, it's important to me. LM258DT not suitable for the normal operation of the pilot? If not - could you in your spare time help find the right amplifier for these purposes in this online store? https://lcsc.com/products/Low-Power-OpAmps_602.html. It's very uncomfortable for me to take your free time, so I apologize. I found everything else, only the amplifier remained.

Hi, Chris! I ordered this operational amplifier, I will test it. Thank you very much for your help!!! :)

Login or Signup to post a comment