Texas Instruments provides a recommended PCB layout in the datasheet, which includes keeping the input and output traces short and away from each other, using a ground plane, and placing decoupling capacitors close to the power pins.
The gain resistors should be chosen based on the desired gain and bandwidth of the amplifier. A higher gain requires smaller resistors, while a lower gain requires larger resistors. The datasheet provides a gain resistor selection table to help with this process.
The maximum power dissipation of the OPA4658P is dependent on the ambient temperature and the thermal resistance of the package. The datasheet provides a power dissipation calculation formula and a thermal resistance table to help determine the maximum power dissipation for a given application.
Yes, the OPA4658P can be used as a unity-gain buffer by connecting the output to the inverting input and using a gain resistor of 0 ohms. However, this configuration may not provide the best noise performance, and a dedicated unity-gain buffer amplifier may be a better choice for some applications.
The OPA4658P has internal input protection diodes, but these diodes may not be sufficient for all applications. External protection devices such as clamping diodes or voltage-limiting resistors may be necessary to protect the amplifier from input overvoltage.
OPA4658P datasheet
by Texas Instruments
