The Role of the Analogue Front End in Smart Manufacturing

Image Source: Mouser Electronics

By David Pike for Mouser Electronics

Published May 21, 2025

Modern smart technology depends on data. Whether connecting the operations of a smart factory or enabling the latest self-guided vehicles, these technologies rely on the feedback of an array of sensors. The information they collect creates an accurate picture of the world around them. Machines can use the model created by this data to interact with the real world, whether to avoid hazards, reconfigure functions to cope with new demands, monitor their condition, or request maintenance. Much of the information received from the sensor will be in the form of low-voltage analogue signals, requiring conversion before it can be processed digitally. The analogue front-end (AFE) is a solution that bridges the gap between analogue sensors and the latest digital processors.

The Limitations of Microcontrollers

The microcontroller unit (MCU) is a critical component of modern electronic equipment. The MCU comprises several components, including the processor, its dedicated memory resources, communication interfaces, and a range of peripheral devices. In some cases, these may include an analogue-to-digital converter (ADC), vital for any MCU intended to process the signals received from analogue sensors.

However, while the MCU can receive these signals, this does not constitute its primary role. At the heart of the MCU’s limitations when processing analogue signals is that it is a digital device. The basic ADC fitted to many MCUs is adequate for sensing tasks in which accuracy is not critical. However, for any applications that rely on precision, a dedicated 16-bit or 24-bit ADC will provide much better results.

The MCU's digital functionality is also a limitation when it comes to digital noise. Analogue signals are very sensitive to interference, requiring isolation and signal conditioning. Digital MCUs will achieve poor signal-to-noise ratios without these dedicated functions, especially when processing low-voltage signals. Any application that accurately senses small fluctuations is vital and will require better performance than the average MCU can deliver.

These basic ADC functions also lack the specialist functionality of dedicated analogue components. The wide dynamic range of a combination of different types of sensors will require additional circuitry, adding to the complexity of the printed circuit board design and increasing the number of components required.

Therefore, when the time comes to handle large numbers of analogue inputs from a broad range of sensor types, MCUs face significant challenges.

The Analogue Front-End Solution

The solution to this challenge is to employ a resource dedicated to receiving large volumes of analogue signals and preparing them for processing by digital devices. The AFE is a device that is placed between the sensors and the MCU. Its primary function is to receive the raw signals created by the sensors and prepare them for conversion. The simplest AFEs carry out a task known as signal conditioning. The signals received by the AFE are amplified, boosting them to the level at which they can be reliably converted into a digital signal and then filtered to remove unwanted noise.

However, the latest AFEs include high-resolution analogue-to-digital conversion using 16-bit or 24-bit technology. This means that the output from the AFE is a clean, digital signal that is ready for processing when it reaches the MCU. Removing the need for the MCU to conduct its own analogue-to-digital conversion greatly simplifies and speeds up its functioning, allowing the data to be processed more quickly and improving response times.

Using an AFE also provides logistical and cost benefits. Replacing potentially complex circuitry with an AFE simplifies the printed circuit board (PCB) design, shortening the time to market. It also reduces the number of components on the bill of materials, and, as the MCU no longer requires on-board analogue-to-digital conversion, it allows the designer to choose a lower-cost option.

Providing the Solution

NXP is a company that understands the limitations of digital processors when handling large volumes of analogue signals. While it manufactures a broad range of MCUs suitable for demanding applications in the automotive and smart factory sectors, NXP’s AFEs bring new levels of capability to the customer.

The NXP N-AFE family of highly configurable analogue front-end devices (Figure 1) is ideal for the latest factory automation applications that rely on sensors. The N-AFE devices are available in options for 16 or 24 bits, high speed or low power, four or eight inputs, and factory-calibrated or non-calibrated offerings. Despite their ability to receive multiple signals, each input can be configured for specific tasks and differentiated for the requirements of different types of sensors, from voltage and current to temperature or pressure.

Figure 1: Block diagram of a typical industrial application with NAFE13388 controlling various analogue inputs and sensors. (Source: NXP)

The NAFE13388-UIM 8-Channel AFE Arduino Shield Board is designed to evaluate the NAFExx388, This Arduino-compatible shield showcases a compact hardware design and enhanced software configurability with universal open-CMSIS driver packs. More universal evaluation is feasible with the NAFEx88-EVB Evaluation Boards, which are not limited to the Arduino form factor.

This NAFE13388-UIM shield is also compatible with the NXP FRDM-MCXN947 board, part of NXP's low-cost, compact, and scalable MCX N Series FRDM boards for rapid prototyping using the NXP MCUXpresso integrated development environment (IDE). These boards feature the MCX N Series microcontrollers, which address a wide range of applications and feature high levels of integration, on-chip accelerators, intelligent peripherals, and advanced security.

N-AFE Overview

The accuracy and precision of the N-AFE family make them invaluable for industrial automation customers. Enhanced precision allows greater quality control in manufacturing, improving yield and reducing waste. They can also play an important role in the maintenance of the factory itself. Accurate sensing within the machinery of the factory can provide early warning of potential failures, allowing operators to conduct maintenance before the production line comes to a halt, reducing downtime caused by unexpected failures.

The N-AFE devices reduce the complexity of PCB design and offer greater precision. These advantages create a more productive manufacturing environment, with increased throughput and fewer unplanned line stoppages. The N-AFE series from NXP delivers high-precision, configurable AFE solutions that streamline board design, improve signal accuracy, and help create the factory of the future.

David Pike is well known across the interconnect industry for his passion and general geekiness. His online name is Connector Geek.