The Google search term "analog-to-digital converter selection" has generated thousands of hits, proving that this task continues to challenge many of our people involved in designing elusive perfect sensing solutions. After all, from simple 10-bit ADCs integrated in 8-bit microcontrollers (MCUs) to ADCs capable of GHz rate resolution, there are a large number of analog-to-digital converter (ADC) solutions.
Unless you are designing a dedicated sensing front end, you are likely looking for an integrated ADC that delivers high quality performance without sacrificing power savings or operational flexibility. In this article, I've listed some parameters that can help you narrow down your ADC's search range, but depending on your application's specific needs, you may have additional parameters.
Resolution. Perhaps the most debated ADC parameter, there are many questions about whether the number of bits that the ADC can solve is the most important measurement of its accuracy. An easy way to look at it is by checking what the application does after the ADC conversion. For example, to measure whether a temperature change has occurred, is it a relative measurement? If so, a 10-bit or 12-bit ADC would suffice because this is a real fake - no problem. On the other hand, consider products such as electric meters. In this application, analog-to-digital conversion requires a high degree of accuracy. The accuracy of the load current measurement may mean the difference in energy usage and therefore billing the utility company. This type of application typically uses >16-bit delta-sigma ADCs.
Sampling Rate. The sampling rate of the ADC is directly dependent on the frequency of the input. Thanks to our scholar friend Nyquist, you know that the ADC must sample with > 2 times the input signal (Fsample ≥ 2x Finput), and you know that there is a minimum required sample rate. For example, a 100 kHz input needs to be sampled at ≥200 kHz. However, the sampling rate specified in the data sheet only covers the true "sampling + conversion" clock - without taking into account any setup time of the ADC, post-processing converted results are used to make decisions or move off-chip data. These factors are equally important because they allow you to calculate the period and duty cycle of the ADC conversion and therefore calculate the remaining margin for post processing.
For example, an ADC sample of 1 MSPS will acquire 1,000 16-bit samples in 1 ms. If you use the double buffering method to capture ADC samples, then you know that you have ≤1ms of time to process the data buffer, take action based on the results, and possibly move the data before the next data set is ready for processing.
Reference selection. An important criterion when evaluating an integrated ADC is the availability of an internal precision reference source. In some cases, the ability to set multiple reference voltage ranges ensures flexibility in addressing different input ranges of the ADC.
Operating range. Many ADCs operate within a limited portion of the total supply voltage range available for the device. It is important to assess the needs of the application in this regard. For example, in battery-powered applications, it may be necessary to drop to the lowest supply voltage range (1.8V is typical for MCUs, although some of TI's Simplel inkTMMSP432P4 series can operate below 1.72V) to ensure reliable Convert until the device is turned off.
Input channel. The number of input channels is not just the number of externally available pins that can be used to connect analog inputs. When choosing an ADC for a set of inputs that require sequencing, it is also important to consider the flexibility of the channel configuration. The optional reference source, dedicated interrupt and conversion registers, and the availability of differential inputs and configurable data formats are key features that ensure that your ADC configuration can be efficiently set up and set up in a customizable manner to prevent wasted cycles during installation.
As I mentioned at the beginning of this article, depending on what the application is trying to perceive, your actual ADC selection criteria list may be longer. You can evaluate the MSP432P4's high-performance ADCs and provide up to 16-bit accuracy by purchasing the MSP432P4 LaunchPadTM Development Kit and quickly getting a tutorial on using precision ADCs through our Simplel ink Academy training portal.
If you want to delve into the topic of ADC selection, see how TI's MSP432P4 high-precision ADC can be stacked on the market with the most up-to-date analog-to-digital converters. Take a look at the chart in Figure 1 below and check out our application report. Useful tips for revealing ADC data sheet parameters.
Desktop Phone Holder,Desktop Mobile Phone Holder,Adjustable Desktop Phone Holder,Universal Desktop Cell Phone Holder
Ningbo Luke Automotive Supplies Ltd. , https://www.car-phone-holder.com