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OPA2188: can OPA2188 support 740 ohm load?

Part Number: OPA2188
Other Parts Discussed in Thread: OPA2191, OPA2196

Hi,

customer want to use OPA2188 in their system. a full differential circuit on OPA2188 is used to sense system output current.

V+=20V, V-=0V, single power supply.

the output of OPA2188 is called VILOCAL, there are 4 below circuits are added to VILOCAL point. every circuit is added to MCU ADC point.

so the load resistor is (750+2210)/4=740 ohm,

can OPA2188 support 740 ohm load?

thanks.

  • Hey Max, 

    Probably ok, hard to say definitively without the full circuit - several considerations, but the one you probably want it the increase in headroom with output current - turn your load question into an output V_I question and see if you are ok, 

  • Hi Max,

    It looks like the total maximum steady state load current for the circuit would be about 6 mA. I agree with Michael's assessment that the OPA2188 would likely be able to the drive the load. However, the OPA2191 or OPA2196 with their higher current output capability (see Output Voltage Swing vs Output Current datasheet Fig's 18 and 19) would be a more certain choice. Here's a link to the OPA2191 datasheet:

    http://www.ti.com/lit/ds/symlink/opa191.pdf

    Regards, Thomas

    Precision Amplifiers Applications Engineering