Skip to main content

Digital to Analog Converter ( DAC )


Digital to Analog Converter   (DAC)


DAC stand for Digital to Analog Converter . It is a system that converts a digital signal into an analog signal. Example, When you hear digital recordings, you’re actually listening to an analog signal that was converted from digital by a DAC. 
              DACs are commonly used in music players to convert digital data streams into analog audio signals. They are also used in televisions and mobile phones to convert digital video data into analog video signals which connect to the screen drivers to display monochrome or color images.
            Any time a signal is converted from one format to another, there is a potential loss of quality. Therefore, it is important to have a high-quality DAC whether you are converting audio or video signals.


Applications

1.     Audio :- The most common use for a DAC is to convert digital audio to an analog signal. This conversion typically takes place in the sound card, which has a built-in DAC. The digital signal, which is basically a stream of ones and zeros, is transformed into an analog signal that might take the form of an electrical charge. This electrical charge is recognized by most speaker inputs and therefore can be output to a speaker system. The audio DAC is a low-frequency, high-resolution type.

2.     Video :- DACs are also used for converting video signals. Previously, most video displays, such as TVs and computer monitors used analog inputs. But now from the last couple of years, digital displays with DVI and HDMI connections have become common. Therefore, in order for a computer to output to an analog display, the digital video signal must be converted to an analog signal. This is why all video cards with an analog output (such as a VGA connection) also include a DAC. The video DAC is a high-frequency low- to medium-resolution type.

3.  Display Electronics :- The graphic controller will typically use a lookup table to generate data signals sent to a video DAC for analog outputs such as Red, Green, Blue (RGB) signals to drive a display.
4.     Motor Control :- Many motor controls require voltage control signals, and a DAC is ideal for this application which may be driven by a processor or controller.
5.     Software Radio :- A DAC is used with a Digital Signal Processor (DSP) to convert a signal into analog for transmission in the mixer circuit, and then to the radio’s power amplifier and transmitter.
6. Data Distribution System :- Many industrial and factory lines require multiple programmable voltage sources, and this can be generated by a bank of DACs that are multiplexed. The use of a DAC allows the dynamic change of voltages during operation of a system.

Types of DAC

1.     Pulse-width modulator
2.     Oversampling DAC
3.     Binary-weighted DAC
4.     R-2R ladder DAC
5.     Cyclic DAC
6.     Thermometer-coded DAC
7.     Hybrid DAC

Labels:

Comments

Post a Comment

Popular posts from this blog

Atanasoff - Berry Computer ( ABC )

The Atanasoff – Berry Computer (ABC)   was the first electronic computer, designed and built by Lowa State College Mathematics and Physics professor John Vincent Atanasoff and his assistant, Clifford E. Berry ( a graduate student) . They worked in the basement of the physics building at Lowa State College on the computer from 1939 until 1942 when it was abandoned due to World War II . Unfortunately, after being abandoned , it was neglected and eventually disassembled for parts. In 1994, a team from Lowa state University began to rebuild the computer, finishing it in 1997. The system weighed more than seven hundred pounds (320 kg). It contained approximately 1-mile (1.6 km) of wire, 280 dual-triode vacuum tubes, 31  thyratrons , and was about the size of a desk.  The idea behind the ABC were later used in the construction of the ENIAC, the world’s first general purpose computer. Purpose / Working ABC was designed only to solve systems of  l...
Post a Comment
Read more

Integrated Injection Logic (I2L)

Integrated Injection Logic (I2L) was disclosed in 1972 at International Solid State Circuits Conference by C. M. Hart and A. Slob of Philips, The Netherlands, and by H. H. Berger and S. K. Wiedmann of IBM, West Germany simultaneously. The basic logic unit is a multiple output inverter which is physically realized as a conventional npn multi-emitter transistor operated in the inverse mode. Base drive to the npn inverters is supplied by multicollector lateral pnp current source transistors. The emitter of the pnp transistor is referred to as the injector, and a single injector distributes base drive to many npn logic units. The outputs of I2L units may be " wire AND " with outputs from other units for NAND implementation of logic functions. I2L is a bipolar LSI circuit technique which achieves high packing density and good power-delay efficiency using conventional bipolar processing. It uses the properties of ion implantation to achieve improved performance ca...
Post a Comment
Read more

Virus

Virus  A virus is a computer code or program, which is capable of affecting your computer data badly by corrupting or destroying them. Computer virus has the tendency to make its duplicate copies at a swift pace, and also spread it across every folder and damage the data of your computer system. A computer virus is a malicious software program or "malware" which, when infecting your system, replicates itself by modifying other computer programs and inserting its own code. Types Of Virus :- File Infector Virus Multipartite Virus Resident Virus Boot Virus Macro Viruss Overwrite Virus Web Scripting Virus Impact of Virus :- Disrupts the normal functionality of respective computer system. Disrupts system network use. Modifies configuration setting of the system. Destructs data. Disrupts computer network resources. Destructs of confidential data. Infected computer programs may include data files, or even the "boot" sector of the hard dr...
1 comment
Read more