Proximity sensors are devices that measure the position and distance of objects without contact, and are used to detect the position of objects in industrial production lines, switches, and so on. Here we present an example of a proximity sensor using an ultrasonic sensor.

Renesas offers combination microcontroller products with built-in analog front-end and op-amps to amplify analog signals. The RA2A1 Group is a representative example of a microcontroller equipped with a responsive sequential comparison type A/D, and the ISL28191 op-amp has low noise and low distortion characteristics. Such features are required for proximity sensors that use ultrasonic sensors.

Block Diagram

Proximity sensor block diagram

Recommended Products


Block Recommended Products Features
Analog Front-End MCU RA2A1 This features a high-performance Arm® Cortex®-M23 core. It has a variety of digital peripheral functions and 24-bit ⊿ΣADC and 16-bit SARADC analog functions, along with measuring and processing analog signals from sensors; it can also be used with a USB or touch human interface.
RL78/I1E Equipped with analog front-end including an optimal 24-bit ΔΣA/D converter for flow rate, pressure, weight, and distortion measurement, etc., for where high-precision measurement is required, such as for industrial equipment and environmental infrastructure, along with a 12-bit D/A converter and configurable amplifier installed in the low-power RL78 microcontroller. The small 4 mm x 4 mm package contributes to miniaturization of the application.
Sub-MCU for Display RL78/L13 RL78/L13 microcontrollers have a built-in segment LCD driver. Three LCD driving voltage generation methods (external resistance division, capacitive split, and internal voltage boost) are supported, corresponding to a variety of segment LCD panels. Our lineup of products with 64/80 pins and up to 376 segments is ideal for equipment equipped with LCD panels such as measuring instruments.

Communication Driver

Block Recommended Products Features
Communications ZIOL2201 ZIOL2201 is a driver/level shifter IC that supports the communications physical layer of industrial equipment such as sensors and actuators. It is IO Link compliant and can be widely used in a wide range of sensor/actuator application equipment.
ISL32704E ISL32704E is an RS-485 differential bus transceiver that enables two-way communication in industrial IoT networks.
ASI4U-V5 ASI4U-V5 ASSP (Application Specific Standard Product) is the industry's first silicon solution that fully meets the ASi-5 (Actuator Sensor Interface Version 5) standard for industrial networking equipment and is ideal for applications in the Industry 4.0 field. (Currently under development)

Analog and Power

Block Recommended Products Features
Operation Amplifier ISL28291 The ISL28191 is a low noise, low distortion Rail-to-Rail op-amp that is available in a 1.8mm x 1.4mm compact UTQFN package.
  • 1.7nV/√Hz input voltage noise at 1kHz
  • 1kHz THD+N typical 0.00018% at 2VP-P VOUT
  • Harmonic Distortion -76dBc, -70dBc, fo = 1MHz
Power Supply
  • Main specifications:
    Input voltage range: 7 to 28V
    Output voltage: 0.8 to 6V
    Maximum output current: 3A
    Auto PFM (light load, high efficiency) mode
  • Simplify power supply design and shorten turnaround time (TAT) with suggested kits and Renesas microcontrollers.
  • Main specifications: Input voltage range: 4.5 to 16V
    Output voltage range: 0.8 to 6V
    Maximum output current: 3A
    Auto PFM (light load, high efficiency) mode
    Dual channel DC/DC
  • Simplify power supply design and shorten turnaround time (TAT) with suggested kits and Renesas microcontrollers.
Isolator /
High-speed Communication Photocoupler /
General-purpose (Tr output) Photocoupler
  • Main specifications: 10Mbps small package high voltage
    Small type SO5 package
    Common lead package
  • Ideal for compact systems with high voltage tolerance

Please see Renesas' comprehensive "Winning Combination" solutions for other solutions.