Category: Interfacing ICs

Sample and Hold Circuit

Sample and Hold Circuit: Four basic sample and hold circuit are shown in Fig. 14.141. In these circuits a JFET is used as switch. During the sampling time the JFET switch is turned on, and the holding capacitor charges up to the level of the analog input voltage. At the end of this short sampling […]

Sample and Hold IC

Sample and Hold IC: Sample and Hold IC – For accurate analog to digital conversion the analog input voltage should be held constant during the conversion cycle. If the analog input voltage changes by more than ± 1/2 LSB an error can occur in the digital output code. To illustrate the effect of a changing […]

IC 7109 Features

IC 7109 Features: The IC 7109 Features are namely, IC 7109 is a 12-bit dual slope A/D converter. It has polarity and overrange bits. It has byte organized TTL compatible three-state outputs and UART handshake mode for simple parallel or serial interfacing to microprocessor systems. It has RUN/HOLD input and STATUS output, which can be […]

ADC0808 Pin Diagram

ADC0808 Pin Diagram: The ADC0808 Pin Diagram and ADC 0809 are monolithic CMOS devices with an 8-channel multiplexer. These devices are also designed to operate from common microprocessor control buses, with tri-state output latches driving the data bus. The main features of ADC0808 Pin Diagram are : 8-bit successive approximation ADC. 8-channel multiplexer with address […]

ADC0804 Family

ADC0804 Family: The ADC0804 Family are ADC0803, ADC0804 and ADC0805 are CMOS 8-bit successive-approximation analog to digital converters. These devices are design to operate from common microprocessor control buses, with tri-state output latches driving the data bus, and are identical except for accuracy. Pin Diagram of ADC0804 Family: Fig. 14.120 shows the pin diagram of […]

DAC0830 Digital to Analog Converter

DAC0830 Digital to Analog Converter: The DAC0830 Digital to Analog Converter is an advanced CMOS 8-bit DAC designed to interface directly with the 8080, 8048, 8085, Z80, and other popular microprocessors. A deposited silicon-chromium R-2R resistor ladder network divides. the reference current and provides the circuit with excellent temperature tracking characteristics (0.05% of Full Scale […]

IC 1408 DAC Pin Diagram

IC 1408 DAC Pin Diagram: The IC 1408 DAC Pin Diagram is an 8 bit R/2R ladder type D/A converter compatible with TTL and CMOS logic. It is designed to use where the output current is linear product of an eight bit digital word. Fig. 14.108 shows the pin diagram and block diagram for IC […]

8279 Keyboard Display Controller Interfacing with 8085

8279 Keyboard Display Controller Interfacing with 8085: Fig. 14.98 shows the 8279 Keyboard Display Controller Interfacing with 8085 in I/O mapped I/O technique. Here RD and WR signals are activated when IO/M signal is high, indicating I/O bus cycle. Reset out signal from 8085 is connected to the Reset signal of the 8279. CLK input […]

Operating Modes of 8279

Operating Modes of 8279: The Operating Modes of 8279 provides 3 basic input modes : Scanned keyboard Scanned sensor matrix Strobed input Scanned Keyboard: In this mode, keyboard can be scaned in two ways : Encoded scan and decoded scan. Encoded scan : In the encoded scan, scan lines (SL2-SL0) are decoded externally to provide […]

8279 Block Diagram

8279 Block Diagram: Fig. 14.84 shows the 8279 Block Diagram. It consists of four main sections CPU interface and control section Scan section 8279 Keyboard section Display section 1.CPU Interface and Control Section: This section consists of data buffers, I/O control, control and timing registers, and timing and control logic. Data Buffers The data buffers […]