Archive for the ‘Conversion Circuits’ Category

Monolithic/Hybrid Analog To Digital (A/D) Converter

The basic ANALOG TO DIGITAL (A/D) CONVERTER CIRCUIT has already been explained in an earlier post. Apart from it, there are also many types of monolithic analog to digital converters, such as the integrating A/D, integrating A/D with three-stage outputs, and the tracking A/D with latched outputs. In addition to this, the outputs of A/D are coded in straight binary, binary-coded decimal (BCD), complementary binary (l’s or 2′s), sign-magnitude binary, and so on. The figure below illustrates an 8-bit monolithic CMOS analog to digital converter with three-state output. The converter is made compatible with a microprocessor and it also exhibits…

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Analog to Digital Converters (A/D)

This type of converter is used to convert analog voltage to its corresponding digital output. The function of the analog to digital converter is exactly opposite to that of a DIGITAL TO ANALOG CONVERTER. Like a D/A converter, an A/D converter is also specified as 8, 10, 12 or 16 bit. Though there are many types of A/D converters, we will be discussing only about the successive approximation type. Successive Approximation Type Analog to Digital Converter A successive approximation A/D converter consists of a comparator, a successive approximation register (SAR), output latches, and a D/A converter. The circuit diagram is…

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Monolithic/Hybrid Digital to Analog Converters

Earlier, I had explained two DIGITAL TO ANALOG CONVERTERS. Both of them have been designed for four inputs. But, if the number of inputs is more than four, the combination of output becomes more than 16. This makes the circuit more complex and the accuracy of the circuit reduces. Therefore, in critical and complex applications, a monolithic/hybrid D/A converter IC must be used. With the help of binary-weighted resistor, and R  and 2R resistor methods, 8-bit,10-bit, 12-bit, 14-bit, and 16-bit D/A converters can be designed with a current output, voltage output, or both current and voltage outputs. The most commonly…

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Digital to Analog Converters (D/A)

A D/A Converter is used when the binary output from a digital system is to be converted into its equivalent analog voltage or current. The binary output will be a sequence of 1′s and 0′s. Thus they ma be difficult to follow. But, a D/A converter help the user to interpret easily. Basically, a D/A converter have an op-amp. It can be classified into 2 types. They are 1. Digital to Analog Converter using Binary-Weighted Resistors 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…

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Voltage Level Detector Circuit

This circuit is designed and submitted by Mr. Rakesh Bute. We are really thankful for his contribution. The circuit as explained by Rakesh: The design came from the interest of finding a new technique of analog to digital conversion. The two types of ADC (Analog to Digital Converter) that inspired me in the development of this circuit are Flash Type ADC and Successive Approximation Type ADC.  The Flash Type ADC is the fastest ADC available in the market (highest sampling rate 120 Msps) but it uses a huge number of OP-AMPS. On the other hand Successive Approximation Type ADC uses…

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Frequency to voltage converter

Frequency to Voltage converter circuit based on TC9400 IC. Description. A very simple and low cost frequency to voltage converter based on the TC9400 IC from Microchip is shown here. TC9400 can be either wired as a voltage to frequency converter or frequency to voltage converter and it requires minimum external components. The functional blocks inside the TC9400 includes integrator opamp, 3uS delay circuit, one shot circuit, charge discharge control circuit, divide by 2 network and necessary drivers. This circuit finds application in a range of electronic projects like frequency meters, tachometers, speedometers, FM demodulators etc. Circuit diagram. In the…

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Frequency to voltage converter using LM331

Description. LM331 is basically a precision voltage to frequency converter from National Semiconductors. The IC has a hand full of applications like analog to digital conversion, long term integration, voltage to frequency conversion, frequency to voltage conversion. Wide dynamic range and excellent linearity makes the IC well suitable for the applications mentioned above. Here the LM331 is wired as a frequency to voltage converter which converts the input frequency into a proportional voltage which is extremely linear to the input frequency. The frequency to voltage conversion is attained by differentiating the input frequency using capacitor C3 and resistor R7 and…

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Speaker to microphone converter circuit

Description. This circuit is a simple approach for converting a loud speaker into a microphone. When the sound waves fall on the diaphragm of a speaker, there will be fluctuations in the coil and there will be a small proportional induced voltage. Usually this induced voltage is very low in magnitude and useless. Here in the circuit the low voltage is amplified using transistors to produce a reasonable output. The transistor Q1 is wired in common base mode and produces the required voltage gain. The transistor Q2 is wired as an emitter follower to produce enough current gain. The voice…

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Converting CD-ROM drive to audio CD player

Description. Here is the simplest scheme for converting a CD ROM drive of your computer to a Audio CD player. The minimum requirement for the player is that, it should have a audio output and skip button. Luckily most of the CD ROM’s are equipped with both of these.  The CD ROM drive needs two voltages, 12V & 5V for its operation. So the main objective is to build a suitable power supply for the CD ROM drive. The IC1 (7812) together with associated components produce a regulated 12V DC. The IC2 (7805) together with associated components produce a regulated…

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Light to Frequency converter circuit

A simple Light to Frequency Converter Introduction. Here is the circuit diagram of a effective light to frequency converter circuit that can be used for variety of applications such as light intensity measurement,fun etc. The circuit is based on TLC555, the CMOS version of famous timer IC NE 555. A photo diode is used for sensing the light intensity.The timer IC is wired in astable mode.The leakage current of the reverse biased photo diode is proportional to the light intensity falling on it.This leakage current charges the capacitance C1.When the capacitor voltage reaches 2/3 of the supply voltage the out…

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