msp430 internal op amp?

Question

Electronics

Good afternoon!
I need to connect a microphone to msp430.
I did the following:

But now you need to use the "operational amplifier from the microcontroller". Please tell me: what does this mean and how to do it?

Answer 1

MSP430F2xx series
Similar to 1xx generation, but running at lower power, support up to 16MHz operation. Device Parameters:
.....
Other Integrated Peripherals: Operational Amplifiers , .....

link

Answer 2

a couple of google requests
www.ti.com/lit/ug/tidu443/tidu443.pdf
MSP430F2274 Transimpedance Amplifier (TIDM-TIA) User's Guide
an example of an applied circuit using an integrated amplifier.
www.ti.com/lit/ug/slau144j/slau144j.pdf - microcontroller datasheet.
screenshot of the operational amplifier module.

Answer 3

But now you need to use the "operational amplifier from the microcontroller".
Please tell me: what does this mean and how to do it?

1. First, we draw up a circuit with an external op-amp. I have slight doubts about the performance of your circuit, so I drew my own.
You can also look at the diagram of this board
https://www.sparkfun.com/products/12758
https://cdn.sparkfun.com/datasheets/BreakoutBoards...
The ADC and op-amp of the microcontroller have unipolar power, so the input signal from the microphone needs put it at half the supply voltage level so that the signal is not cut off.
2. We study the scheme of the op-amp module in the microcontroller in the document MSP430x4xx Family User Guide
www.ti.com/lit/ug/slau056l/slau056l.pdf
Figure 22-1. OA Block Diagram, page 649
It is necessary to write certain values ​​to the registers that control multiplexers and other logic elements in order to bring signals to the inverting and non-inverting inputs of the op-amp and output the op-amp output to the internal ADC.
The op-amp can be configured in one of several modes.
Because The op-amp in the 1st paragraph is turned on in the inverting mode, the
General-Purpose Opamp Mode and Inverting PGA Mode, which are set by the OAFCx register, would be suitable.
But, most likely, you will want to set the signal gain yourself with external resistors, so we select the General-Purpose Opamp Mode. That is, OAFCx = 0;
In this case, a bunch of elements become uninteresting to us on the diagram.
Further, we configure OAPx = 0; (from which input to take the signal to the non-inverting input) We take the signal from OAxI0.
OANx = 1; (we take the signal to the inverting input from OAxI1) Turn on the
op-amp with the register OAPMx = 3;
Then we smoke this item, how to bring the signal from the op-amp to the leg to the output and apply the ADC to the input.
We bring it outside to connect the resistors from the outside, which are point 1 on the diagram.
3. Open the datasheet for a specific microcontroller and look for legs.
Application Note www.ti.com/lit/ml/slap118/slap118.pdf - fire. Even if for another series. Thanks Dmitry Mozgovoy