FMA Unit 5.7 Interfacing DAC to 8051

DIGITAL TO ANALOG CONVERTER

DAC0808 is an 8 channel 8-bit digital to analog converter.

Pin Configuration of DAC 0808

                                                      

     ·        Digital Input (A1to A8)

These pins are eight digital input lines with A1 as MSB and A8 as LSB.

     ·        Anolog Outpurt (Io)

         This pin is used to provide analog output in the form of current Io. Therefor                  there  is a need of external current to voltage converter if analog output in the                 form of     voltage is required.

     ·        V_EE

This pin is used to provide supply of 15 V.

     ·        GND

This pin is used to provide ground to the supply

     ·        Vref ⁽⁺⁾ and Vref ^(-) (Reference voltages)

These pins are used to provide positive reference voltage or negative reference voltage depending on the desired polarity of reference voltage.

Interfacing DAC 0808 to 8051

     ·        The output of DAC is a current which is converted into voltage using OPAMP                based Current to Voltage converter.

     ·        The analog output current Io of DAC depends on the Iref flowing into the Vref              terminal and the status of the D0 – D7 bits.

      It can be expressed as,

                               

Questions              

Write a program to generate triangular waveform using DAC.

Draw 8051 based system to interface DAC. Write a program to generate triangular wave

Write an assembly language program to generate triangular waveform using DAC interfaced with 8051 microcontroller

Interface DAC 0808 with 8051 Microcontroller. Write program to generate sawtooth waveform.