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Electronics => Projects, Designs, and Technical Stuff => Topic started by: China NewBoy on November 06, 2019, 11:06:58 am

Title: A problem about OPAmp and TL431
Post by: China NewBoy on November 06, 2019, 11:06:58 am

             How  the voltage between the 2.3 pin of TL431 will change(increase or drop？)   after the input of op amp A and op amp B increases？
 
   the opa A  and opa B are on the same chip

Title: Re: A problem about OPAmp and TL431
Post by: iMo on November 06, 2019, 11:47:25 am

If the voltage at the pin1 against pin2 (gnd) of the TL431 goes above 2.5V the voltage between its pins 3 and 2 drops from Vxyz to 2.5V.
In the schematics above there is a divider 147k/3k thus the voltage at pin 1 most probably never goes above 2.5V.

Title: Re: A problem about OPAmp and TL431
Post by: China NewBoy on November 06, 2019, 01:49:50 pm

thanks,the problem is solved now..casued by my stupid mistake