Renesas reference design for micromobility

Renesas aims to accelerate the development of e-scooters, e-bikes, UPS and energy storage systems with a reference design and optional functional blocks that can be adopted for many 24V-48V applications such as lawn mowers, electric carts, robot cleaners, power tools, power banks, and more.

The motor control and inverter board features synchronized current/voltage measurements and drivers that are pulse width modulated (PWM) to actuate the motor, and monitor motor status. The algorithm with the hardware is ideal for driving brushless DC (BLDC) motors. Also, two optional boards are available: the wireless charging receiver board, and the Bluetooth Low Energy (BLE 5.0) control board.

For system control, the winning combination solution uses a cost optimized, energy-efficient RX23T MCU with built-in floating point unit (FPU) and six high-performance timers specifically tooled for complex inverter control algorithms. These specific features and modular design helps engineers greatly reduce the man-hours in software/hardware development and debug. In addition, unlike other large cell count single-chip battery managers, the highly integrated ISL94216 offers several features that balance and monitor system conditions to improve battery life and safety, independent of the MCU. The winning combination solution also uses the ISL81601 60V bidirectional 4-switch synchronous buck-boost controller for ultra-fast charging. The controller’s CC/CV charger profile is implemented through the system MCU. Key features:

• BFE and charger board

• • ISL94216 16-cell BFE supports up to 200 mA+ external cell balancing – key to enabling fast recharging and high utilization in large battery packs with hot plug tolerance up to 62V
  • BFE provides full high-side, battery protection and monitoring for 4S to 16S cell battery packs
  • Renesas’ RX23T 32-bit MCU with built-in FPU supports full control of entire system
  • Renesas ISL28214 op amps deliver low power consumption and input bias, and the ISL81601 maximizes charging efficiency and uses current sensing and I/O monitoring to adjust input levelsRenesas’ ISL84051 multiplexer handles up to eight inputs with low RDSon connectivity and nanosecond switch timesMotor control and inverter board
  • The motor control and inverter board supports a 48V battery pack and can reach up 5000 RPM using a 1600-watt inverter powertrain with motor control sensors
  • Motor control and inverter board includes a DC/DC converter, ISL28191 op-amp current sensors, ISL80410 LDO regulator, HIP2211 100V half-bridge MOSFET drivers, and MOSFET bank; connects to the BFE and charger board

   

  • Optional boards and mobile phone application
  • BLE control board with RX23W MCU enables secure mobile phone connectivity via BLE for throttle control, battery status, GPS connection, and saved route history; connects to the BFE and charger board. This MCU is specifically chosen from the same RX Family to enable monotonic software design

  • Wireless charging receiver board features two Renesas wireless receivers

    used in parallel to boost output as needed; connects to the BFE and charger board

  • Mobile phone application unlocks scooter, controls ON/OFF power and motor start
  • Mobility solution sends diagnostic and parametric data to mobile phone’s secure BLE channel in 1-second intervals