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RL78/I1B

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Product Longevity: 2034

Low Power Microcontrollers with 24-bit ΔΣ A/D Converter, RTC Backup and High-accuracy Oscillator Ideal for Electricity Meters

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Overview

RL78/I1B microcontrollers adapt various electricity meter metrologies for different regulations by country and realize efficient power measurement by the combination of low active current 96uA/MHz, standby current 0.66uA (Halt mode with 32kHz oscillator and RTC backup on), 24-bit ΔΣA/D converter, phase adjustment circuits and high pass filter. CPU clock frequency can be minimized, taking advantage of the efficient power measurement features, which include the low power ΔΣ A/D converter 0.53mA/ch. RL78/I1B microcontrollers have a +/- 1% high-accuracy high-speed on-chip oscillator with +/-0.05% frequency correction function. The benefit of the accurate on-chip oscillator keeps the system robust even when the external oscillator is stopped.

RL78/I1B Block Diagram
RL78/I1B Block Diagram
  • CPU: RL78 core, Max. 24MHz
  • Voltage: 1.9V to 5.5V
  • Package: 80 to 100-pin QFP
  • Memory: SRAM Max. 8KB, Program Flash Max. 128KB

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Design & Development

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Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on the CAD Model links in the Product Options table. If a symbol or model isn't available, it can be requested directly from SamacSys.

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Resources

Support Communities

  1. RL78 I1B R5F10MMG , Required data flash and store 15 byte in this data flash memory

    Dear Sir, i am using the R5F10MMG MCU in our project and development almost done, we required in end time of project data flash memory for save the 15 bytes in this data flash memory. Please guide me and help for this issues. Thanks & Regards Shivali Singh

    Sep 2, 2021
  2. hi, i am using sigma delta ADC of 16 bit, we get raw data of sample results in signed int type variable, now i have to get squares of these samples in assembly, please guide me how to write code for multiplication in assembly?

    Thanks and Regards  Sachin

    Feb 20, 2018
  3. Emulator E2 lite for serial communication

    Hi Team, Is it possible to use Emulator E2 lite connected to a RL78 target board to communicate to PC serial terminal (for e.g. I want to do some printf/sprintf from the target board and print on the PC's hyperterminal)? Can you guide with the process ...

    Apr 28, 2023
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FAQs

  1. RL78 Family: Relationship between A/D Conversion Resolution and A/D Conversion Time

    ... ✓ (Note)   ✓ ✓ Different B   ✓ ✓ ✓ Same C   ✓   ✓ Different D   ✓     N/E E     ✓ ✓ Different   Group A: RL78/I1B, RL78/I1C, RL78/I1EGroup B: RL78/G23, RL78/G24Group C: RL78/G1A, RL78/G1P, RL78/ ...

    Nov 12, 2024
  2. Tell me the points to be aware of when using the RL78 Code Generator with the WDT.

    In the RL78 Code Generator, the Watchdog Timer (WDT) is set to 'Enabled' by default, as shown in the diagram below. To avoid unintended resets by the WDT, please either select 'Disabled' for the 'Watchdog Timer Operation Setting' or add a program to clear the Watchdog Timer counter.

    Dec 10, 2024
  3. RL78 Family: Is it possible to initialize the on-chip debug security ID?

    ... G1H, RL78/G1M, RL78/G1N, RL78/G1P, RL78/G22, RL78/G23, RL78/G24, RL78/H1D, RL78/I1A, RL78/I1B, RL78/I1C, RL78/I1D, RL78/I1E, RL78/L12, RL78/L13, RL78/L1A, RL78/L1C   Japanese

    Aug 1, 2025
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Videos & Training

The easy-to-build RL78 Quick Solutions feature Renesas' ultra-low power RL78 MCUs and analog devices. These solutions showcase device combinations that improve design performance and power efficiency to support your product development.

News & Blog Posts

Blog Post
Feb 9, 2023
Smart Energy Metering for a Greener Future