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Original question:

TINA/Spice/LMV652: Spice model doesn't behave as the datasheet for frequency response

LMV652: simple voltage follower, not simulating rail to rail

David Reed1
Intellectual 345 points
Part Number: LMV652
Other Parts Discussed in Thread: TLV9052, TLV9001

Hi,

I have a simple Tina TI simulation with the LMV652 and observed that unless I apply a 5V supply voltage I don't see a full 3V swing on my output, the simulation clips at about 2.4V if I use my as designed 3.3V supply.   The datasheet shows it should achieve within 90mV of the 3.3V rail at 3.3V and 25 deg C, figure 10&12. Is the simulation file incorrect or am I misinterpreting the datasheet in some way?

If my simulation is working correctly, could you please recommend a pin compatible (8 pin pkg dual ) that is rail to rail @ 3.3V? Low cost,general purpose, low power but ultra low power is not a requirement. The applications in this design are voltage measurement and temperature measurement, low frequency measurement of slow changing values.

ThanksPBIM V-Sense RPP.TSC

  • 0
    TI__Mastermind 22571 points

    Hello David,

    Your simulation is working correctly, your limitation is your input common mode. From the datasheet, the input common mode only goes from 0-2.1 for a 3V supply. If you are looking to use the same circuit but a different amplifier, I believe you're looking for something with rail to rail inputs and outputs.

    You could use the TLV9052 if you're looking for a 2 channel device with a VSSOP(8) package. Rail to rail input output, slightly higher Iq per channel than LMV652, you sacrifice GBW and gain some slew rate but those don't seem to be critical from your TINA circuit. Placing TLV9052 in where you had LMV652 on your TINA circuit shows no clipping.

    If you are open to looking at a different package amp, TLV9001 is cheaper with lower Iq per channel, and is also rail to rail input/output and works in your TINA circuit.

    Best,
    Jerry