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OPA2187: IB on chopper operation

Daisuke Higa
Genius 4505 points
Part Number: OPA2187
Other Parts Discussed in Thread: OPA188, , OPA187

Tool/software:

Hi support team.

On page 12 of the Technical White Paper, the bias current transient characteristics of the OPA188 during chopper operation are described.

Could you please provide the data for OPA2187?

Best regards,

Higa

  • +1
    TI__Mastermind 26758 points

    Higa,

    Below are the measurements used to develop Table 5-1 in Optimizing Chopper Amplifier Accuracy.  Slide 2 shows the test configurations used.  Slide 3 shows the AC test used to capture the waveforms similar to what you want to see.  Slide 4 shows the DC measured results used to develop Table 5-1.  Slide 5 and 6 illustrate the scope captures for this device.   Note that these measurements are made in a gain of 121 V/V as shown in the circuit on slide 3.  The conclusion that this data supports is that the OPA187 has much smaller bias current transients than OPA188 and the device is can be used with higher source or feedback impedances than most chopper amplifiers (i.e. the offset is not substantially affected by impedances up to 100kΩ.

    Best regards, Art Kay

    OPA187-chopper.pdf