Hardware requirements

  • Type-C USB cable

  • FRDM-MCXN947 board

  • Personal Computer

Board settings Positive input channel0 J4-1(P4_12) and negative input channel J4_3(OPAMP0_INN) connect to GND.

Prepare the Demo

  1. Connect a type-c USB cable between the PC host and the CMSIS DAP USB port (J17) on the board

  2. Open a serial terminal with the following settings (See Appendix A in Getting started guide for description how to determine serial port number):

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo

OPAMP DAC ADC EXAMPLE!

Please input a value (0 - 4095) for DAC:1500 Input DAC value is 1500 Current DAC output is about 1209.000 mV Please press any key excluding key (R or r) to get user channel’s ADC value. Vsw1 ADC value: 1499 Actual voltage on Vsw1: 1.208V Vref ADC value: 1498 Actual voltage on Vref: 1.207V

Vref stands for positive reference voltage output while Vsw1 stands for OPAMP output voltage. 
OPAMP output voltage ranges around 0 to VDDA-0.8V.