analog to digital converter adc0804

Posted on Feb 5, 2014

It is 8-Bit, Microprocessor-Compatible, A/D Converters. Data Collection Analog to Digital Conversion and Communicating and It uses an ADC0804 chip to convert from analog to digital, an AT89C2051. The ADC0802 families are CMOS 8-Bit, successive-approximation A/D converters which use a modified potentiometricladder and are designed to operate with the 8080A control bus via three-state outputs.

analog to digital converter adc0804
Click here to download the full size of the above Circuit.

These converters appear to the processor as memory locations or I/O ports, and hence no interfacing logic is required. The differential analog voltage input has good common mode-rejection and permits offsetting the analog zero-input voltage value. In addition, the voltage reference input can be adjusted to allow encoding any smaller analog voltage span to the full 8 bits of resolution. The functional diagram of the ADC0802 series of A/D converters operates on the successive approximation principle. Analog switches are closed sequentially by successive-approximation logic until the analog differential input voltage [VlN(+) - VlN(-)] matches a voltage derived from a tapped resistor string across the reference voltage. The most significant bit is tested first and after 8 comparisons (64 clock cycles), an 8-bit binary code (1111 1111 = full scale) is transferred to an output latch. The normal operation proceeds as follows. On the high-to-low transition of the WR input, the internal SAR latches and the shift-register stages are reset, and the INTR output will be set high. As long as the CS input and WR input remain low, the A/D will remain in a reset state. Conversion will start from 1 to8 clock periods after at least one of these inputs makes a low to-high transition. After the requisite number of clock pulses to complete the conversion, the INTR pin will make a high-to-low transition. This can be used to interrupt a...

Leave Comment

characters left:

New Circuits



Popular Circuits

Bandpass filter
125Watt 150Mhz amplifier
Basic RF Oscillator circuit diagram
Stability Analysis In Multiple Loop Systems
90S2313 AVR Robot Board
Cuckoo Sound Generator Circuit Schematic
2G—10 Band Stereo Graphic Equaliser circuit diagram
LED fast optical pulse generating circuit diagram
Temperature Sensor MAX6698 7-Channel Smart consisting of circuit diagram