Output voltage (V_out) versus output current (I_out) is usually referred to as the claw curve because they are shaped like an animal claw. Claw curves show the slam limit, or saturated output limit, with respect to output current and temperature. This is particularly important in rail to rail output amplifier models as it can help circuit designers to choose the appropriate op amp especially when driving heavy loads or when dynamic range is a concern. Figure 2-24 shows the data sheet claw curve for TLV9002. Claw curves are composed of two parts, the positive side (claw+) and the negative side (claw-). This value can be given in a data sheet as either absolute or relative. Absolute is when V_out is a specific power-supply voltage, whereas relative is when V_out is a generic power-supply voltage. To learn more about claw curves, please refer to the Texas Instruments Precision Labs video series on input and output limitations.

Op amp models are designed to replicate the claw curve behavior at room temperature or 25°C. Figure 2-25 and Figure 2-27 show the recommended test circuit to simulate sourcing (claw+) and sinking (claw-) curves. The test circuit is a simple inverting buffer circuit with the non-inverting input pin grounded and the output connected to a current generator. Adjust the V_cc and V_ee to match the recommended supply voltage from the data sheet. For claw+ make sure to set V_in equal to V_ee so that the op amp sources current. Similarly for claw- make sure to set V_in equal to V_cc so that the op amp sinks current. Figure 2-26 and Figure 2-28 show the simulated claw curve for TLV9002. This circuit may be simulated by downloading the AN1516 Test Circuits in either TINA-TI™ or PSpice® for TI.