35.3.7 Application Usage

The figure above displays an op amp connected directly to the pins of the device without being connected to any of the internal resistors. This is useful for situations where the user desires to make all connections to other components externally. The multiplexer settings required to achieve this configuration are:

The figure above displays a voltage follower, also known as a unity-gain buffer. The non-inverting (+) input is connected to a pin, and the output is connected to the inverting (-) input. The multiplexer settings required for this configuration are:

The figure above displays a non-inverting Programmable Gain Amplifier. The required multiplexer settings are as follows:

The figure above shows the inverting PGA configuration. The multiplexer settings required are:

The figure above shows how an op amp can be configured as an integrator. An external capacitor and external resistor are required. The DUMPn event closes a switch to discharge the capacitor and reset the integrator. The multiplexer settings required are:

The figure above shows how a differential amplifier can be constructed from two op amps. The differential amplifier accepts two input signals, V1 and V2. The output also consists of two signals, OP1OUT and V2. The difference of the output signals, V_DIFF, is proportional to the difference (V2-V1) of the two input signals. The multiplexer settings required to implement this configuration are as follows:

The figure above shows a cascaded non-inverting PGA constructed from two op amps. The following multiplexer settings are required:

The figure above shows a cascaded inverting PGA constructed from two op amps. The required multiplexer settings are:

The figure above shows a cascaded non-inverting PGA constructed from three op amps. The following multiplexer settings are required:

The figure above shows a cascaded inverting PGA constructed from three op amps. The required multiplexer settings are:

The figure above displays three op amps configured as an instrumentation amplifier. The following multiplexer settings are required:The resistor ladders associated with OP0 and OP2 must be configured as follows to select the desired gain: