Is there a problem with an instrumentation amplifier?
Kaufman and Seidman 8 give a good practical coverage on the general use of amplifiers. Instrumentation amplifiers suffer from a chronic output swing problem, even when the input common mode range and output voltage swing specifications are not violated.
Which is the output stage of an instrumentation amplifier?
The op-amp 3 is a difference amplifier that forms the output stage of the instrumentation amplifier. The output stage of the instrumentation amplifier is a difference amplifier, whose output Vout is the amplified difference of the input signals applied to its input terminals.
Why does my amplifier have a chronic swing problem?
Instrumentation amplifiers suffer from a chronic output swing problem, even when the input common mode range and output voltage swing specifications are not violated. This is because the first stage of an instrumentation amplifier has internal output voltages that can clip at unspecified levels.
How does the impedance of an amplifier affect the gain?
The gain of the amplifier depends only on the external resistors used. Hence, it is easy to set the gain accurately by choosing the resistor values carefully. The input impedance of the instrumentation amplifier is dependent on the non-inverting amplifier circuits in the input stage.
What happens in the first stage of an instrumentation amplifier?
This is because the first stage of an instrumentation amplifier has internal output voltages that can clip at unspecified levels. The clipping itself is invisible to the user, but it affects the output swing adversely, usually causing a gain reduction and thus an invalid result.
What is the offset drift of an instrumentation amplifier?
The offset drift is attributable to temperature-dependent voltage outputs. Figure 2.85 shows the schematic representation of a precision instrumentation amplifier. The relationship between output and input is