Renesas’ 32-bit MCUs Bring Dedicated AFE to Industrial Sensor Systems

November 27, 2023 by Aaron Carman

The latest Renesas MCU includes 32-bit computation with high-performance analog functions.

Expanding its lineup of 32-bit microcontrollers, Renesas has released the RX23E-B family of high-performance MCUs with a high-precision and high-speed analog front end (AFE). The new family expands the existing RX23E-A family and offers designers a new MCU option when high-speed analog sensing is required, but a dedicated AFE is impractical.



The RX23E-B family sports good computation performance with a high-precision and high-speed AFE, allowing designers to reduce BOM costs and the size of their devices. 

Although digital electronics are useful when it comes to computing, communications, and many other fields of electrical engineering, analog sensing is still a requirement for many industrial applications. As such, the new RX23E-B family provides new tools to bolster the next generation of devices.

This article takes a closer look at the new family of MCUs and their target applications and how designers can leverage these features in their own devices.


High-Speed Analog

Similar to its predecessor, the RX23E-B family includes a 32-MHz RXv2-based CPU with included DSP instructions and FPU support. Both devices include a 24-bit sigma-delta (ΣΔ) ADC, precisely measuring analog signals without requiring a dedicated chip.


The RX23E-B block diagram

The RX23E-B block diagram highlights the features of the chip family, including the high-precision AFE and supporting digital electronics to enable 32-bit computation performance. Image used courtesy of Renesas

Where the two families differ, however, is the AFEs. Compared to the RX23E-A family, the RX23E-B family  (datasheet linked) supports faster data rates and better noise performance, making the new family better suited for high-precision or high-speed applications. The RX23E-B family supports up to 125 kSPS and an RMS noise level of 0.256 µVrms. As such, the RX23E-B targets applications prioritizing fast responses, high-frequency sampling, and SNR.


Industrial Performance and Control

In addition to the AFE, the new MCU family includes up to 256 KB of Flash and 32 KB SRAM, lower precision DACs and ADCs, an LCD controller, and connectivity support. With these features, Renesas has particularly targeted industrial sensing applications, but any designer requiring good noise performance and high-speed sampling can benefit from the improved AFE.


The improved analog noise and sampling performance of the onboard AFE

The improved analog noise and sampling performance of the onboard AFE allows the RX23E-B family to aid a variety of applications outside of industrial sensing.

To showcase the benefits of the RX23E-B family, Renesas has developed an example pressure control application where the onboard AFE senses two independent pressure sensors. The MCU also controls two solenoid valves and an external LCD, all while using only a single MCU.

The RX23E-B family is available now with different feature combinations in various packages, along with a starter kit from Renesas to allow designers to get up and running quickly.


Integrating More Tools in One

Renesas claims the new RX23E-B family offers improved noise performance, improved sampling rate, and better integration.


The RX23E-B family

The RX23E-B family is available in a variety of packages to provide optimal area efficiency. 

Although Renesas has identified industrial automation as a key use case, the versatility of the MCU could impact much broader applications.



All images used courtesy of Renesas