4 Bit Analogue to Digital Converter

The operation of the converter is based on the weighted adding and transferring of the analogue input levels and the digital output levels. It consists of comparators and resistors. In theory, the number of bits is unlimited, but each bit needs a comparator and several coupling resistors. The diagram shows a 4-bit version. The value of the resistors must meet the following criteria:

• R1:R2 = 1:2;
• R3:R4:R5 = 1:2:4;
• R6:R7:R8:R9 = 1:2:4:8.

The linearity of the converter depends on the degree of precision of the value of the resistors with respect to the resolution of the converter, and on the accuracy of the threshold voltage of the comparators. This threshold level must be equal, or nearly so, to half the supply voltage. Moreover, the comparators must have as low an output resistance as possible and as high an input resistance with respect to the load resistors as feasible. Any deviation from these requirements affects the linearity of the converter adversely.

Circuit diagram:

4-Bit Analogue to Digital Converter Circuit Diagram

If the value of the resistors is not too low, the use of inverters with an FET (field-effect transistor) input leads to a near-ideal situation. In the present converter, complementary metal-oxide semiconductor (CMOS) inverters are used, which, in spite of their low gain, give a reasonably good performance. If standard comparators are used, take into account the output voltage range and make sure that the potential at their non-inverting inputs is set to half the supply voltage. If high accuracy is a must, comparators Type TLC3074 or similar should be used. This type has a totem-pole output. The non-inverting inputs should be interlinked and connected to the tap of a a divider consisting of two 10 kΩ resistors across the supply lines. It is essential that the converter is driven by a low-resistance source. If necessary, this can be arranged via a suitable op amp input buffer. The converter draws a current not exceeding 5 mA.

Source :www.extremecircuits.net

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Digital Dice Circuit diagram

This is digital dice circuit diagram.Here I have used IC CD4060B.After pressing.S2 to to play you will be able to listen a sound too.I think this will be a wonderful circuit for you all.now you can play your games with your digital dice.



Note
# This circuit operates with 9V power supply
# Build this circuit on a PCB.

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PT2399 Digital Echo Circuit

Digital Echo Processor IC PT2399 is using CMOS technology in audio purposes. Digital Echo Processor PT2399 is implementing the system in the process of ADC and DAC audio repro echo.


Digital Echo Processor PT2399 has a high sampling frequency and 44K memory. Digital Echo Processor PT2399 to repro echo digital audio system of repro VCO delay time system that can be arranged. Digital Echo Processor PT2399 has a very low audio distortion of (THD <0.5%) and very low noise as well (No <-90dBV) so that the Digital Echo Processor PT2399 is capable of providing good audio quality.

Digital Echo Schematics

Description:
Setting the external resistor from 10 K Ohm to 50 K Ohm. If the value is greater then the Delay Time also increases.

• Echo Digital Application Processor PT2399
• Video Tape Recorder
• Video Compact Disk
• Television
• CD Player
• Car Stereo
• KARAOKE Mixer
• Electronic Musical
• Echo Audio Processor

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