File Name: different types of adc and dac .zip
The digital signal is represented with a binary code, which is a combination of bits 0 and 1. Observe that in the figure shown above, an Analog to Digital Converter ADC consists of a single analog input and many binary outputs. In general, the number of binary outputs of ADC will be a power of two. This chapter discusses about the Direct type ADCs in detail. If the ADC performs the analog to digital conversion directly by utilizing the internally generated equivalent digital binary code for comparing with the analog input, then it is called as Direct type ADC.
A counter type ADC produces a digital output, which is approximately equal to the analog input by using counter operation internally. The control logic resets the counter and enables the clock signal generator in order to send the clock pulses to the counter, when it received the start commanding signal.
The counter gets incremented by one for every clock pulse and its value will be in binary digital format. This output of the counter is applied as an input of DAC. DAC converts the received binary digital input, which is the output of counter, into an analog output. At this instant, the output of the counter will be displayed as the digital output.
A successive approximation type ADC produces a digital output, which is approximately equal to the analog input by using successive approximation technique internally. The control logic resets all the bits of SAR and enables the clock signal generator in order to send the clock pulses to SAR, when it received the start commanding signal. The binary digital data present in SAR will be updated for every clock pulse based on the output of comparator.
The operations mentioned in above steps will be continued until the digital output is a valid one. A flash type ADC produces an equivalent digital output for a corresponding analog input in no time. The 3-bit flash type ADC consists of a voltage divider network, 7 comparators and a priority encoder. The voltage divider network contains 8 equal resistors. The voltage drop across each resistor from bottom to top with respect to ground is applied to the inverting terminal of comparators from bottom to top.
At a time, all the comparators compare the external input voltage with the voltage drops present at the respective other input terminal.
That means, the comparison operations take place by each comparator parallelly. All the outputs of comparators are connected as the inputs of priority encoder.
The flash type ADC is used in the applications where the conversion speed of analog input into digital data should be very high. Previous Page. Next Page. Previous Page Print Page. Dashboard Logout.
An ADC may also provide an isolated measurement such as an electronic device that converts an input analog voltage or current to a digital number representing the magnitude of the voltage or current. Typically the digital output is a two's complement binary number that is proportional to the input, but there are other possibilities. There are several ADC architectures. Due to the complexity and the need for precisely matched components , all but the most specialized ADCs are implemented as integrated circuits ICs. These typically take the form of metal—oxide—semiconductor MOS mixed-signal integrated circuit chips that integrate both analog and digital circuits.
There are two basic type of converters, digital-to-analog (DACs or D/As) and unnecessary with these ADCs, there is no need to allocate separate chip area for.
The digital signal is represented with a binary code, which is a combination of bits 0 and 1.
Your email address will not be published. Required fields are marked *