Figure 7-12 illustrates a 2X overdrive triangle waveform for the THS4551. The input resistor is driven with a ±9-V swing for the gain of 2-V/V configuration in the test circuit of Figure 8-1 using a single 5-V supply. When the output maximum swing is reached at approximately the supply values, the increasing input voltage turns on the internal protection diodes across the two input pins. The internal protection diodes are two diodes in series in both polarities. This feature clamps the maximum differential voltage across the inputs to approximately 1.5 V when the output is limited at the supplies but the input exceeds the available range. The input resistors on both sides limit the current flow in the internal diodes under these conditions.