Nitin Bhambri
Sr. Manager, System and Solution Team
Published: March 2, 2023

Consider you are traveling to a remote area in your electric vehicle, and there is limited access to charging stations. What if you scan your mobile application, which shows an off-board charger in your vicinity, that you can use, but you don’t know whether it is compatible with your EV? This can be resolved by interoperable EV chargers.

Renesas provides a solution for 3KW off-board EV chargers which integrates the EV charging solution. The solution comes with an industry-leading interleaved PFC R2A20112ASP, which maintains a high power factor, gives wider operational voltage, and can compensate for fluctuations over AC lines. This solution is controlled using a 32-bit microcontroller from Renesas’ RX-Family, RX66T, which enables zero voltage soft switching (ZVS) with synchronous rectification for a reliable and efficient system. The RX66T is based on Renesas' latest RXv3 core architecture supporting a DSP instruction set and FPU unit. The RX66T also incorporates high resolution PWM timers along with advanced security & safety functionality.

3KW off board EV Charger

Figure 1. 3KW off-board EV Charger

To provide interoperability, the Renesas OIC solution (OCPP Interface card) adds intelligence to any standalone charger. The addition of intelligence under the communication Standard ISO15118 allows the charger to adjust the output voltage so that fast charging can be offered to the user.


Figure 2. OCPP Interface Card (OIC)

OIC contains different communication devices like the BLE module (DA14531MOD), Wi-Fi Module (DA16200MOD) or the BLE + Wi-Fi module (DA16600MOD) and GSM/NB-IoT (RYZ024A). Renesas’ RA2L1 is based on an ARM cortex M23 core microcontroller which has CAN and PWM interfaces for a CCS charge gun. The PMOD interface adds flexibility to communicate with different off-board chargers.


Figure 3. Communication Diagram

OCPP helps the Charger and CSMS (Charging Station Management System) to communicate with each other through an open platform. The Open Charge Point Protocol (OCPP) is an open-source communication standard for EV charging stations and network software companies. Simply put, any EV charging station that is OCPP-compliant can be configured to run any similarly OCPP-compliant software. It offers multiple benefits to users:

  • Connect any CSMS with any charging station.
  • Agnostic of EV-EVSE charging protocol.
  • Procure chargers from multiple vendors.
  • New features can be easily added.
  • Supports smart charging compliance with other open protocols.

System Benefits:

  • Wide operating range for universal implementation.
  • Soft switching ZVS to provide high efficiency, lower thermal losses, and reliable system solution.
  • OCPP/Intelligence will give the flexibility to use the charger with any vehicle.

To find out more about this winning combination and others, please visit to help you get to market more quickly. 

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