The DAC08 series of 8-bit monolithic digital-to-analog converters provide very high speed performance coupled with low cost and outstanding applications flexibility. Advanced circuit design achieves 85 ns settling times with very low glitch energy and at low power consumption. Monotonic multiplying performance is attained over a wide 20 to 1 reference current range. Matching to within 1 LSB between reference and full-scale currents eliminates the need for full-scale trimming in most applications. Direct interface to all popular logic families with full noise immunity is provided by the high swing, adjustable threshold logic input.
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The DAC IC is a monolithic digital to analog converter which takes an 8-bit digital data as an input and sends an analog signal at the output. It has high accuracy and utilizes very low power. Electronic devices like music players, televisions, mobiles, CD players gaming systems, etc. In the real world, most of the data is in the form of analog signals. Therefore, we need a device that can perform digital to analog conversion.
For example, a microphone takes an analog audio signal as an input which is converted into a digital signal so that the computer can process it by adding effects and removing noise. Now, if you want to run a speaker, we need to convert this digital signal back to an analog signal. As you can depict from DAC pinout diagram that it consists of 16 pins. We will see in Proteus simulation about how to set these parameters.
It takes parallel input in the form of 8-bits. The DAC chip converts this digital input into a current. We convert this current into an analog voltage by connecting a resistor at the output. The figure below shows a simple circuit which uses DAC The IC changes this input into a current. The output voltage obtained through LM IC is linearly proportional to the digital inputs.
The above circuit is also known as the current to voltage converter as it is converting a current to an analog voltage. In this example circuit, we designed a circuit that generates an analog voltage output between volts. This is a 4-bit counter IC but we need 8-bit input data. Therefore, we connected two 74LS93 counter ICs in cascading. Now output pins of these counters will count from Reference voltage defines the output voltage range of analog output signal from op-amp output. Pin14 and Pin15 are Vref- and Vref- pins respectively that are used to set reference voltage of output signal.
In a similar way, we can set any reference voltage within a specified limit according to the datasheet. The clock signal connected with counters ICs changes counter value from 0,1,2… and to a maximum value on every positive edge of the clock cycle. Digital to analog converter IC converts this input data into analog output voltage.
The output signal magnitude is directly proportional to 8-bit input signal and reference voltage value. However, as you know that reference voltage will be constant for most of the time like in the above example circuit. This graph shows the simulation result transient analysis of the above-given circuit. As you can see from this proteus simulation graph, voltage is changing linearly from 0 to a maximum voltage of 10 volts according to the 8-digit input signal.
Input signal changes on every positive edge of a clock cycle. Notify me of follow-up comments by email. Notify me of new posts by email. Table of Contents. Download Datasheet. These are the eight bits of DAC input. A1 is the first bit or MSB of that input and A8 is the least significant bit of input applied.
DAC0808 PDF Datasheet浏览和下载
The chip accuracy of conversion is good and power consumption is also low to make it popular. The power supply currents of the DAC are independent of bit codes, and exhibits essentially constant device characteristics over the entire supply voltage range. DAC IC is used in applications where a digital to analog conversion is required. The chip used to be popular a decade ago and its applications used to be many but at present there are many modern IC which can perform DAC with higher resolution, speed and efficiency. So this device is mainly used for reference and beginner applications and nothing more.
Datasheet Texas Instruments DAC0808