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OPA862: Output value when OPA862 single power supply?

Part Number: OPA862
Other Parts Discussed in Thread: TINA-TI


It was configured the same as OPA862 DATASHEET 19PAGE (Figure 7-4. Typical Single-Supply Configuration), and PD=GND was connected. However, the output does not 2V/V and a negative value is output.

(VOD=-3.4V for 1V input, VOD=-1V for 2V input)

Yellow is pin 4 (VOUT+) and blue is pin 5 (VOUT-).

What could be the cause? Need additional circuits?

  • Hi Kwon,

    here a TINA-TI simulation with ideal OPAmps:


  • Hi kai~

    When sbomaz9c(OPA862 TINA-TI Spice Model (Rev. C))  is received and executed from TI,

    VOD = -1V output when 2V input is obtained as in the previous test result.

    I want to know the method of VOD=1V/V OR 2V/V with a single power supply as shown on page 19 of the OPA862 data sheet.

    Best Regards,


  • Hello Kwon,

      It looks like your sims match up with your measurements. Kai's simulation shows how output voltage and differential voltage changes with input voltage. This matches up with Figure 8-3 in OPA862 datasheet. 

       Using single-supply configuration shown in Figure 8-2:

       The output voltage is gained by 2V/V via differential measurement. Tina-TI file attached below. 

       For DC voltages, an input voltage of 1V will be 1V from first stage buffer. With second stage biased at 2.5V, this will show as 4V output since feedback will keep voltage the same on each input. Therefore, it will be a differential of the two DC voltages with a gain of 2V/V. 


    Thank you,


  • Thank you for your help.