A digital to analog converter is an electronic device that converters a digital signal into analog format. On the other hand, an analog to digital converter is an electronic device that converters an analog signal into digital format. Both DAC (Digital to Analog Converter) and ADC (Analog to Digital Converter) play an important role in different fields of electronic such as communication, signal processing, computing technologies, control and automation systems, and more.

With the advancement of technology, we can design and implement the analog to digital converters and digital to analog converters in the form of IC or integrated circuits. This chapter is meant for explaining some important ADC and DAC ICs commonly used in electronic circuits and systems.

What are DAC and ADC ICs?

DAC and ADC ICs are small electronic devices and integrated circuits used in the field of electronics to convert a digital signal into analog format and analog signal into digital format respectively.

The ADC IC (Analog to Digital Converter IC) is used to convert analog signals into digital format. These ICs take the analog signals as input and sample them at regular intervals of time. Then, they produce digital representation of the analog input signal as output.

There is another type of IC called DAC IC (Digital to Analog Converter IC) that is used to convert digital signals into analog format. Hence, the DAC ICs take digital signals as input and produce their analog representation as output.

The ADC and DAC ICs are important components in several different types of electronic systems where converting signals between the analog and digital formats are crucial.

Popular DAC and ADC ICs

The following are some commonly used DAC and ADC ICs that are widely used in various electronic applications −

• ADC 0809 (8-Bit ADC IC)
• ICL 7109 (12-Bit Binary ADC IC)
• DAC 0808 (8-Bit DAC IC)

Let us discuss about these ADC and DAC ICs in detail along with their features and applications.

ADC 0809 IC

The ADC 0809 IC is an analog to digital converter IC. It is a monolithic CMOS device that consists of an 8-bit analog to digital converter, an 8-bit multiplexer, and a microprocess compatible control unit.

The ADC 0809 IC uses successive approximation technique to perform analog to digital conversion. It comes in a 28-pin molded IC carrier package. The pin diagram of the ADC 0809 IC is shown in the following figure.

This IC is one of the widely used ADC ICs in various digital electronics and microcontroller-based circuits and systems to convert analog signals into their digital format.

Features of ADC 0809 IC

Some of the key features of ADC 0809 IC are listed below −

• The ADC 0809 IC is an 8-bit analog to digital converter IC. Hence, it can represent an analog input signal with a resolution of 8 bits or 2⁸ = 256 possible discrete values in digital format.
• The ADC 0809 IC provides an easy interfacing with all
  microprocessors.
• It does not require the external zero or full-scale adjustments.
• It also consists an 8-channel single ended analog signal multiplexer.
• It can operate ratiometrically or with a 5 V DC voltage or an analog span adjusted voltage reference.
• The output of the ADC 0809 IC meets the TTL voltage level requirements.
• The ADC 0809 IC can operate with low power consumption, typically 15 mW that makes making it best suited for batterypowered devices.
• It can support 0 V to 5V input analog voltage range with a single supply of 5 V DC.
• It has a conversion time of around 100 µs.

Applications of ADC 0809 IC

The ADC 0809 IC is an ideal device in various applications such as automation, process and machine control, consumer electronics, automotives, etc. Some common applications of this ADC IC are listed here −

• The ADC 0809 IC is most commonly used in data acquisition systems to convert analog input signals received from sensors, transducers, and other analog measuring devices into digital format to process and analyze them using digital systems.
• The ADC 0809 IC is also used in different applications in the field of instrumentation and control engineering. It is mainly employed for precise measurement and monitoring of analog signals like temperature, pressure, and motor control.
• In the field of industrial automation, the ADC 0809 IC is used for digitalization of analog process and control signals which are then used for automation and monitoring of control and manufacturing processes.
• The ADC 0809 IC is also used in various consumer electronic devices such as digital multimeters, audio and music systems, etc. for providing an interface between analog signals and digital circuits.

ICL 7109 IC

The ICL 7109 IC is a monolithic 12-Bit analog to digital converter (ADC) IC primarily designed for easy interfacing with microprocessor-based systems and Universal Asynchronous Receiver-Transmitter (UART).

The ICL 7109 IC comes in a 40-pin IC package whose pin configuration diagram is shown in the following figure −

Features of ICL 7109 IC

Some of the key features of the ICL 7109 ADC IC are described below −

• The ICL 7109 IC is a 12-bit dual slope integrating analog to digital converter IC. Hence, it provides a resolution of 12-bits that enables it to represent the analog input signals with a higher precision in digital format.
• The ICL 7109 IC provides an easy interfacing with microprocessors. This feature makes it ideally suitable for applications where analog signals are required to be processed or analyzed using digital systems like computers.
• The ICL 7109 IC also provides facility of interfacing with UART (Universal Asynchronous Receiver/Transmitter) systems. This feature allows for serial data transmission and communication with external digital devices. It also has some control lines like RUN/(HOLD)’ inputs and STATUS output that can be used to monitor and control the conversion timing.
• The ICL 7109 IC does not require any special handling precautions because its all inputs are fully protected against static discharge.
• The ICL 7109 IC provides true differential input and differential reference. It provides low noise and high accuracy.
• The ICL 7109 IC offers a low drift typically less than 1 μV/°C. This ensures high precision in analog to digital conversion under varying environmental conditions.
• The ICL 7109 IC consumes les power that makes it ideally suitable for battery powered devices.

Applications of ICL 7109 IC

The ICL 7109 IC is one of the commonly used analog to digital converter IC in various digital and microprocessor based systems. Here are some common examples of applications of the ICL 7109 IC −

• The ICL 7109 IC is commonly used in digital systems where accurate and high-performance conversion of analog signals into digital format is needed. It widely used in industrial monitoring, instrumentation, and scientific measurement systems.
• Since the ICL 7109 IC is compatible with Universal Asynchronous Receiver/Transmitter (UART) systems. Hence, it is used for interfacing between industry standard UARTs for transmission of digital data serially over communication channels.
• In industrial automation and control systems, the ICL 7109 IC is employed for converting analog process and control signals into digital data for processing and controlling by microprocessors and microcontrollers.
• Due to high accuracy and low power consumption, the ICL 7109 IC is best suited to utilize in battery powered testing and measuring instruments, where precise measurement of analog signals is desired.
• The ICL 7109 IC is also used in numerous consumer electronic devices for converting analog signals into digital format accurately, which is crucial for proper functioning of the device.

DAC 0808 IC

The DAC 0808 IC is an 8-bit digital to analog converter IC designed to convert a digital input signal into its analog representation. It is a monolithic IC known for its high accuracy and low power consumption in digital to analog conversion process.

This IC comes in the dual-in-line IC package with 16 pins. The following depicts the pin diagram of the DAC 0808 IC.

Due to its features like high accuracy, low power consumption, and fast settling time, it is commonly used in microcontroller-based and other digital electronic systems.

Features of DAC 0808 IC

The following are the key features of DAC 0808 IC, making it best suited to use in digital systems −

• The DAC 0808 IC has a resolution of 8-bits. Hence, it can convert a digital input signal into the analog format precisely. It provides high accuracy in digital to analog conversion. Typically, it can convert a digital signal into analog format with a maximum error of around $\mathrm{\pm 0.9 \%}$.
• The DAC 0808 IC produces a full-scale current match, typically $\mathrm{\pm 1}$ LSB. This feature helps maintain the relative accuracy in the output current.
• The DAC 0808 IC has a fast-settling time typically 150 ns. Thus, this IC can adjust its output to match the desired analog voltage in a very short time.
• The DAC 0808 IC is compatible with both TTL and CMOS devices.
• The DAC 0808 IC has a high-speed multiplying input slew rate. Therefore, it can change its output voltage at a very fast speed when the digital input to it changes. Typically, the slew rate of the DAC 0808 IC is 8 mA/µs.
• The DAC 0808 IC can operate with a power supply voltage range varying from $\mathrm{\pm 4.5}$ V to $\mathrm{\pm 18}$ V. This feature makes it versatile to use in systems operating at different voltage levels.
• The DAC 0808 IC consumes very low power. Typically, it consumes only 33 mW of power at an operating voltage of $\mathrm{\pm 5}$ V. This feature makes it suitable to use in battery power devices where energy efficiency is critical.

Applications of DAC 0808 IC

The DAC 0808 IC is widely used in a variety of applications across different fields such as audio signal processing, industrial automation, and control systems for the conversion of digital signals into analog voltages. Some key
examples illustrating the applications of the DAC 0808 IC are given below −

• The DAC 0808 IC is very commonly used in waveform generators to produce analog output voltages from digital input data. It allows us to produce various types of waveforms like sine waves, square waves, triangular waves, etc.
• In the field of instrumentation and control, the DAC 0808 IC is employed for producing analog signals that can be used in calibration, simulation, and testing applications.
• The DAC 0808 IC is also used in motor control circuits to produce analog voltage signals from digital inputs. These analog output signals are then used for operating motor drives, actuators, and servo systems.
• The DAC 0808 IC is also used in various audio systems such as audio playback systems, synthesizers, musical instruments, audio effects processors, etc. to perform digital to analog conversion.
• In industrial automation and control systems, the DAC 0808 IC is utilized to produce analog signals used to control and regulate the processes, operate the valves, and adjust the system variables based on digital inputs provided by microcontrollers or PLCs.

Conclusion

There are several different ADC and DAC ICs available in the market and are used depending on the specific requirements of the application. In this chapter, we explained the pin diagram, key features, and applications of some popular types of DAC and ADC ICs.

In conclusion, a DAC IC is a digital to analog converter chip that can convert digital input signals into analog output voltages at a very high speed and efficiency. On the other hand, an ADC IC is an analog to digital converter chip that converts analog input signals into digital output signals. These ICs are so designed that they are compatible with various digital systems and low power devices.