Microchip simplifies on-board charger solution design

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With the market for Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles (PHEVs) continuing to grow rapidly a critical application for EVs is the on-board charger, which converts AC power into DC power to recharge the vehicle’s high-voltage battery.

Credit: Microchip

Microchip Technology has developed an On-Board Charger (OBC) solution that uses a selection of its automotive-qualified digital, analogue, connectivity and power devices. These include the dsPIC33C Digital Signal Controller (DSC), the MCP14C1 isolated SiC gate driver and mSiC MOSFETs in an industry-standard D2PAK-7L XL package.

This solution has been designed to increase an OBC system’s efficiency and reliability by leveraging the dsPIC33 DSC’s advanced control functions, the MCP14C1 gate driver’s high-voltage reinforced isolation with robust noise immunity and the mSiC MOSFETs’ reduced switching losses and improved thermal management capabilities.

To further simplify the supply chain for customers, Microchip can provide the key technologies that support the other functions of an OBC, including communication interfaces, security, sensors, memory and timing.

To accelerate system development and testing, Microchip is offering a flexible programmable solution with ready-to-use software modules for Power Factor Correction (PFC), DC-DC conversion, communication and diagnostic algorithms. The software modules in the dsPIC33 DSC are designed to optimise performance, efficiency and reliability, while providing the flexibility to customise and adapt to specific OEM requirements.

“Microchip established an E-Mobility megatrend team with dedicated resources to support this growing market, so in addition to providing the control, gate drive and power stage for an OBC, we can also provide customers with connectivity, timing, sensors, memory and security solutions,” explained Joe Thomsen, corporate VP of Microchip’s digital signal controller business unit. “Microchip can offer comprehensive solutions to streamline the development process, including automotive-qualified products, reference designs, software and global technical support.”

An overview of the key components in this OBC solution includes:

  • The dsPIC33C DSC is AEC-Q100 qualified and features a high-performance DSP core, high-resolution Pulse-Width Modulation (PWM) modules and high-speed Analog-to-Digital Converters (ADCs), making it optimal for power conversion applications. It is functional, safety ready and supports the AUTOSAR ecosystem.
  • The MCP14C1 isolated SiC gate driver is AEC-Q100 qualified and is offered in SOIC-8 wide-body package supporting reinforced isolation and SOIC-8 narrow-body supporting basic isolation. Compatible with the dsPIC33 DSC, the MCP14C1 is optimised to drive mSiC MOSFETs via Undervoltage Lockout (UVLO) for VGS = 18V gate drive split output terminals, which simplifies implementation and eliminates the need for an external diode. Galvanic isolation is achieved by leveraging capacitive isolation technology, which results in robust noise immunity and high Common-Mode Transient Immunity (CMTI).

The mSiC MOSFET in an AEC-Q101-qualified D2PAK-7L XL surface mount package includes five parallel source sense leads to reduce switching losses, increase current capability and decrease inductance. This device supports 400V and 800V battery voltages.