![double buffered parallel to serial converter. double buffered parallel to serial converter.](https://s3.manualzz.com/store/data/017390091_1-30dd81ef904f47db8f1b188ba5f67226-360x466.png)
Instrumentation and Communication Systems.All DACs contain double buffered data inputs, which allow all analog outputs to be simultaneously updated using the asynchronous LDAC input. The complete transfer function of each individual DAC can be shifted around the V BIAS point using an on-chip Sub DAC. The channel control registers allow individual control of DACs. The system control register has control over all DACs in the package. On-chip control registers include a system control register and channel control registers. V SWING is derived internally from V BIAS. These DACs provide output signals in the form of V BIAS V SWING. These parts operate from a +3.3 V to +5 V (10%) power supply and incorporates an on-chip reference. Serial ADCs are discussed at the end of this section.The AD7804/AD7808 are quad/octal 10-bit digital-to-analog converters, with serial load capabilities, while the AD7805/AD7809 are quad/octal 10-bit digital-to-analog converters with parallel load capabilities. In parallel ADC, we have 8 or more pins dedicated to bringing out the binary data, but in serial ADC we have only one pin for data out. The ADC chips are either parallel or serial. Conversion time is defined as the time it takes the ADC to convert the analog input to a digital (binary) number. In addition to resolution, conversion time is another major factor in judging an ADC.
![double buffered parallel to serial converter. double buffered parallel to serial converter.](https://hackaday.com/wp-content/uploads/2019/03/sqr-5.png)
In this chapter we examine several 8-bit ADC chips. The higher-resolution ADC provides a smaller step size, where step size is the smallest change that can be discerned by an ADC. An ADC has n-bit resolution where n can be 8, 10, 12, 16 or even 24 bits. Therefore, we need an analog-to-digital converter to translate the analog signals to digital numbers so that the microcontroller can read and process them. Sensors for temperature, velocity, pressure, light, and many other natural quantities produce an output that is voltage (or current). Transducers are also referred to as sensors. A physical quantity is converted to electrical (voltage, current) signals using a device called a transducer. Temperature, pressure (wind or liquid), humidity, and velocity are a few examples of physical quantities that we deal with every day. Digital computers use binary (discrete) values, but in the physical world everything is analog (continuous). Analog-to-digital converters are among the most widely used devices for data acquisition.