OPA656 is a broadband, unity gain stable, field-effect transistor input operational amplifier 2

application information

Broadband and glare free operation

OPA656 provides a unique combination of broadband, unified gain stability, and DC precision trimming JFET input stage for voltage feedback amplifiers. Its 230MHz high gain bandwidth product (GBP) can be used to provide high signal bandwidth for low gain buffers or to provide broadband, low-noise transient bandwidth for photodiode detector applications. To achieve the full performance of OPA656, careful attention needs to be paid to the layout of the printed circuit board (PCB) and component selection, as described in the rest of this data sheet.diode

Figure 1 shows the non-invasive gain of the+2 circuit, which serves as the basis for most typical characteristics. Most curves are characterized using a signal source with a driving impedance of 50 ohms, and the measuring equipment displays a load diode impedance of 50 ohms. In Figure 1, the 50 ohm parallel resistor at the VI terminal matches the source impedance of the test generator, while the 50 ohm series resistor at the VO terminal provides a matching resistor for the load of the measuring device. Usually, the voltage swing specification of the data table is located at the output pin (VO in Figure 1), while the output power specification is at the matched 50 Ω load. The total output load of 100 ohms at the output, combined with the total feedback network load of 500 ohms, indicates that the OPA656 effective output load of the circuit in Figure 1 is 83 ohms.diode