# digital to analog converters

Posted on Feb 6, 2014

A D/A converter using binary-weighted resistors is shown in the figure below. In the circuit, the op-amp is connected in the inverting mode. The op-amp can also be connected in the non-inverting mode. The circuit diagram represents a 4-digit converter. Thus, the number of binary inputs is four. We know that, a 4-bit converter will have 24 = 16 com

Click here to download the full size of the above Circuit.

binations of output. Thus, a corresponding 16 outputs of analog will also be present for the binary inputs. Thus, according to the position (ON/OFF) of the switches (bo-b3), the corresponding binary-weighted  currents will be obtained in the input resistor. The current through Rf will be the sum of these currents. This overall current is then converted to its proportional output voltage. Naturally, the output will be maximum if the switches (b0-b3) are closed The output is a negative going staircase waveform with 15 steps of -). 5V each. In practice, due to the variations in the logic HIGH voltage levels, all the steps will not have the same size. The value of the feedback resistor Rf changes the size of the steps. Thus, a desired size for a step can be obtained by connecting the appropriate feedback resistor. The only condition to look out for is that the maximum output voltage should not exceed the saturation levels of the op-amp. Metal-film resistors are more preferred for obtaining accurate outputs. If the number of inputs (>4) or combinations (>16) is more, the binary-weighted resistors may not be readily available. This is why; R and 2R method is more preferred as it requires only two sets of precision resistance values. A D/A converter with R and 2R resistors is shown in the figure below. As in the binary-weighted resistors method, the binary inputs are simulated by the switches (b0-b3), and the output is...

Leave Comment

characters left:

• ## New Circuits

.

Popular Circuits

Wah pedal for Guitar
Rgb-blue-box
Digital-frequency-window
The electronic blood manometer based on MSP430F449 is designed
home-made light-operated camera trigger
Flame Sensor
tr switch
Flip-Flop Timer Using 4017
250 kV High Voltage DC Power Supply with Neat Trick for Switching Polarity
1971 lincoln continental: post connectors fuse box good cant find
Automatic Switch For Voltage Converters
Computer Circuit

Top