**Digital to analog converter**

Digital binary signals are converted into analogue signals using digital to analogue converters.

**Types of digital to analogue converter**

Generally, two types of digital to analogue converters are used, the binary weighted

Input D/A converter and R/2R ladder D/A converter.

**Binary weighted input D /A converter**

The binary weighted input D/A converter is based on a summing circuit which sums the input current based on binary output and represents it as a voltage output. In the binary input method, a resistor network is used with resistor values representing the binary weights of the input bits of digital code. The binary is applied at the resistor inputs. A current will flow through the resistor of input voltage applied at the resistor inputs. A current will flow via the resistors in the input voltage logic applied is high. No current will flow via resistor if the input voltage applied is logic low. The magnitude of the current flowing via each resistor depends on the value of the resistor. The total current flow via each resistor adds up and flows via the feed back resistor Rf, which is connected via output and the inverted input of op – amp. The output voltage of op – amp is determine by the voltage drop across Rf resistance.

**Figure:** 4 bits digital to analogue converter

**My Lab Experiment**

I have implemented a D/A converter using 741C operation amplifier. The D/A is** **connected to a binary counter(7493). The binary counter input is drive using 1 Hz clock which is also created by my own.

**Figure:** 4 bits digital to analogue converter