## Wednesday, October 12, 2011

### 4-BIT D/A CONVERTER

4-BIT D/A CONVERTER

Aim: To verify analog output voltages for the digital input data using 4-bit D/A converter (R-2R method).

Apparatus:
1.     4-bit D/A converter kit
2.     Connecting wires
3.     patch cards
4.     Multimeter
5.     CRO
Circuit Description:

For this operation op-amp is connected in inverting configuration. The binary inputs are simulated by switches b0 through b3 and the output is proportional to the binary inputs. Binary inputs can either be in the high (+5 volts) or low (0 volts) state. The output equation is given by

Use Rf  = 11  k and R = 11 k

For Example:

When b3 is high and all other inputs are low then the output voltage is

= -2.5 volts.

Circuit Diagram:

Procedure:

1.     Study the operation of the circuit.
2.     As the circuitry is already wired you just have to trace the circuit according to the circuit diagram given above.
3.     Connect trainer to the mains and switch on the power supply.
4.     Measure the output voltages of regulated power supply circuit that is +12 volts and -12 volts.
5.     Note down output voltages for different combinations of digital inputs and compare it with the theoretical value.

Result: