The OPA695 provides output voltage and current capabilities consistent with driving doubly-terminated 50-Ω lines. For a 100-Ω load at a gain of +8 V/V (see Figure 6-1), the total load is the parallel combination of the 100-Ω load and the 456-Ω total feedback network impedance. This 82-Ω load requires no more than 45 mA of output current to support the ±3.7-V minimum output voltage swing specified for 100-Ω loads. This value is much less than the minimum ±100-mA specifications.

For the specifications described previously, consider voltage and current limits separately. In many applications, the voltage times the current (or V-I product) is more relevant to circuit operation; see also Figure 5-21. The X and Y axes of this graph show the zero-voltage output current limit and the zero-current output voltage limit, respectively. The four quadrants provide a more detailed view of the OPA695 output drive capabilities. Superimposing resistor load lines onto the plot shows the available output voltage and current for specific loads.

To maintain maximum output-stage linearity, no output short-circuit protection is provided. No short-circuit protection is not normally a problem, as most applications include a series-matching resistor at the output that limits the internal power dissipation if the output side of this resistor is shorted to ground.

However, shorting the output pin directly to the adjacent positive power supply pin, in most cases, destroys the amplifier. If additional short-circuit protection is required, consider a small series resistor in the power-supply leads. Under heavy output loads, this series resistor reduces the available output voltage swing. A 5-Ω series resistor in each power-supply lead limits the internal power dissipation to less than 1 W for an output short circuit, while decreasing the available output voltage swing only 0.25 V for up to 50-mA desired load currents. Always place the 0.1-μF power supply decoupling capacitors directly on the supply pins after these supply current-limiting resistors.