DAC Interfacing with 8085 Microprocessor
1 DAC 0800 Features
ü To convert the digital signal to analog signal a Digital-to-Analog Converter (DAC) has to be employed.
ü The DAC will accept a digital (binary) input and convert to analog voltage or current.
ü Every DAC will have "n" input lines and an analog output.
ü The DAC require a reference analog voltage (Vref) or current (Iref) source.
ü The smallest possible analog value that can be represented by the n-bit binary code is called resolution.
ü The resolution of DAC with n-bit binary input is 1/2nof reference analog value.
2 Circuit Diagram of DAC 0800
ü The DAC0800 is an 8-bit, high speed, current output DAC with a typical settling time (conversion time) of 100 ns.
ü It produces complementary current output, which can be converted to voltage by using simple resistor load.
ü The DAC0800 require a positive and a negative supply voltage in the range of ± 5V to ±18V.
ü It can be directly interfaced with TTL, CMOS, PMOS and other logic families.
ü For TTL input, the threshold pin should be tied to ground (VLC = 0V).
ü The reference voltage and the digital input will decide the analog output current, which can be converted to a voltage by simply connecting a resistor to output terminal or by using an op-amp I to V converter.
ü The DAC0800 is available as a 16-pin IC in DIP.
Table 3.2 ADC Conversion Table
Square Wave Generation Using DAC 0800
