Analog front end mounted 32-bit microcontroller ideal for high precision sensing, test and measurement equipment

The RX23E-A group microcontrollers are equipped with an analog front end that can measure temperature, pressure, flow, and weight with less than 0.1% precision without calibration, making it ideal for high-precision sensing, test and measurement equipment. The CPU is equipped with an RXv2 core that excels in DSP / FPU operations, enabling high-accuracy measurement, control, and communication with a single chip.

Key Features

Analog Front End Features

  • Dual 24-bit delta sigma A/D converters: Up to 23-bit effective resolution, Programmable data rate 7.6 sps to 15,625 ksps
  • PGA: Rail-to-rail analog input, Gain 1 to 128, Offset drift 10 nV/°C, Gain drift 1 ppm/°C
  • Voltage Reference: Low drift 4ppm/°C with good temperature stability
  • Excitation Current Source: Matched programmable current source

MCU Features

  • CPU: 32-bit RXv2 (32 MHz), DSP/FPU for digital signal processing
  • Interface: SPI x 1 ch, UART x 4 ch, I2C x 1 ch, CAN x 1 ch

RX23E-A Block Diagram


(x = Code for memory size, y = Code for operating ambient temperature)

Items RX23E-A
Pin Count 48 pin 40 pin
Product name R5F523ExAyFL R5F523ExAyNF
Analog Front End (AFE) 24-bit Delta-Sigma A/D Converter

- 2 units, Data Rate 7.6 sps to 15.6 ksps
- Up to 23-bit effective resolution
- Simultaneous 50/60 Hz rejection

- Reference voltage external input compatible (dual input)

- Synchronous start function

- Fourth-order sinc filter

- Offset error/Gain error correction function


- Rail-to-rail analog input, Gain 1 to 128

- Gain drift 1 ppm/°C
- Offset drift 10 nV/°C

- RMS noise 30 nVrms

Analog Input Differential 6 inputs or Single end 11 inputs Differential 4 inputs or Single end 7 inputs
Voltage Reference
2.5 V ± 0.1 %, Temperature drift 4 ppm/°C
Excitation Current Source

- Max. 4 channels, 50 to 1000 uA

- Current matching ±0.2%
- Drift matching 5 ppm/°C

Temperature Sensor 1 unit, Accuracy ± 5 °C
Bias Voltage Generator 1 unit, Output voltage AVCC0/2
Low-side Switch 1 unit, On-resistance 10 Ω
Voltage Detector

- Low power-supply-voltage detector
- Delta-sigma A/D input voltage fault detectors
- Delta-sigma A/D reference voltage fault detectors and disconnect detectors
- Excitation current source disconnect detectors

12-bit A/D Converter 6 channels x 1 unit 4 channels x 1 unit
CPU Core - RX CPU v2 core, General purpose register: 32-bit x 16
- Multiplier : 32-bit multiplier
- Divider : Available
- Multiply-Accumulate : Available (Inter-memory operation and Inter-register operation)
Operating Frequency 32 MHz
Floating Point Operation Unit Single precision floating point unit (Support Addition/Subtraction/Compare/Multiple/Divide or other instruction)
Code Flash 128 KB (x=5), 256 KB (x=6)
Data Flash 8 KB
SRAM 16 KB (x=5), 32 KB (x=6) 
Clock Generator - Main Clock Oscillator : 1 MHz to 20 MHz (VCC≧2.4V), 1 MHz to 8 MHz (VCC<2.4V)
- High-speed On-chip Oscillator : 32 MHz
- Low-speed On-chip Oscillator : 4 MHz
- PLL Frequency Synthesizer : 24 MHz to 32 MHz (VCC≧2.4V)
- IWDT Dedicated On-chip Oscillator : 15 kHz
Interrupt NMI, IRQ0 - IRQ7
Event Link Controller Available
DMA DMA Controller 4 channels
Data Transfer Controller Available
Timer Multi-function Timer Pulse Unit2 6 channels
Port Output Enable2 POE0# - POE3#, POE8#
8-bit Timer 2 channels x 2 units
Compare Match Timer 2 channels
Low Power Timer 1 channel
Independent Watchdog Timer Available
Communication Interface Serial Communicaion Unit (SCIg, SCIh) 4 channels 3 channels
IIC-Bus Interface (RIICa) 1 channel
Serial Peripheral Interface (RSPIa) 1 channel
CAN Module (RSCAN) 1 channel
IO Port General Purpose I/O 21 17
Safety Function A/D converter self-diagnosis function/ Disconnection detection assist function,
Clock frequency accuracy measurement circuit, Independent Watchdog Timer etc.
Power Supply Voltage AVCC0 : 2.7 to 5.5 V (In the case of 12-bit A/D Converter, 1.8 to 5.5 V)
VCC:1.8 to 5.5 V
Operating Ambient Temperature –40 to +85°C (y=D), –40 to +105°C (y=G)
Package LFQFP (7 x 7 mm, 0.5 mm pitch) HWQFN (6 x 6 mm, 0.5 mm pitch)

Pin Count / Memory Size Lineup:

Program Flash

256 KB
32 KB
128 KB
16 KB

You can find an explanation of orderable part numbers here.

Resources for Software and Hardware

Title Description
My Renesas Create a My Renesas account to use our tool download services, receive e-newsletter/update notifications, and take advantage of our other services.
e-learning Information for studying and learning about microcontrollers and microprocessors.
FAQ Frequently asked questions and useful hints for development.
Forum A forum and community site to share technical information, questions and opinions with others who use Renesas products.


Software Design Support

Title Description
e² studio This integrated development environment (IDE) is based on the popular combination of the open-source Eclipse IDE and its CDT plug-in that enables C/C++ language development.
CS+ This integrated development environment (IDE) can be used for coding, assembly, compiling, and simulation. CS+ is also included with starter kits.
E2 emulator Lite This entry-level on-chip debugging emulator provides functionality equivalent to that of the E1 emulator at a low price.
E2 emulator This on-chip debugging emulator has advanced features that improve the efficiency of development. In addition to the basic functions from debugging to flash programming, this emulator supports hot plug-in and external triggers as standard items. This emulator also helps to reduce development time by downloading at high speeds (compared to the E1 emulator) and the ability to work in combination with various solutions such as the tuning of current drawn by systems under development.
E20 emulator This on-chip debugging emulator has enhanced debugging facilities such as large-capacity tracing and real-time RAM monitoring when used in combination with RX600 and RX700 MCUs (this emulator provides debugging functionality equivalent to that of the E1 emulator for other MCUs).
E1 emulator This on-chip debugging emulator is a standard model which provides basic debugging functions (production is to be discontinued at the end of December 2019).


Hardware Design Support

Title Description
IBIS/BSDL IBIS standard simulation data is required for high-speed board design and can be used to run simulations to examine and troubleshoot issues such as waveform reflection, ringing, and so on, before producing the actual board.
BSDL is a data input format supported by most IEEE 1149.1 (JTAG)-compliant tools. The automatic test pattern generation (ATPG) and automatic test equipment functions of these tools facilitate testing.
Resonator Information

Please search for your resonator on its manufacturer's site linked below. If you require optimal oscillation circuit constants for your particular system, please ask the manufacturer of the oscillator.


For Main clock resonator :

KYOCERA: Click here for RX23E-A oscillation evaluation result.

Murata Manufacturing: For IC Manufacturer, select Renesas Electronics, and enter R5F523E into the IC Part Number search box.

You can filter the sample codes and application notes that are displayed using the below filters.

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