Microchip Releases Chipset Solution for Designing Onboard EV Chargers
The new design on-board charger (OBC) chipset and accompanying white paper provide a trusted path forward for battery EV and plug-in hybrid vehicle designers.
Microchip has announced a new onboard charger (OBC) solution that combines the company's intelligence, power factor correction, signal generation, and high-voltage, and high-current drive components. These include Microchip's dsPIC33C digital signal controller (DSC), the MCP14C1 isolated SiC gate driver, and SiC MOSFETs. The solution promises to speed up time to market for EV developers for both battery-powered EVs and plug-in hybrid EVs.
Microchip combined EV onboard charging components.
Microchip has also released a white paper alongside the OBC outlining how it can improve charge movement into a battery pack and back out again.
Control
For many years, designers have used the Microchip dsPIC in motor control power inverters and charging circuits. In addition to providing the basics, like high-resolution pulse width modulation (PWM) and analog-to-digital converters (ADC), the dsPIC offers advanced digital signal processing functions to help with the feedback and analysis aspects of power electronics.
The dsPIC33C DSC microcontroller family is AEC-Q100 qualified for use in automotive applications. The microcontrollers feature a dual-core architecture. One core can be dedicated to control and automotive communications, while the other handles signal processing and complex tasks like power factor corrections and modulation. Separating these tasks increases both performance and reliability.
The dsPIC's signal processing capabilities enhance control algorithms, voltage regulation, and current limiting. The DSP's efficient algorithms deliver highly controlled charging under a wider variety of scenarios.
Drive
The MCP14C1 isolated gate driver is also AEC-Q100 qualified. It comes in multiple chip packaging: the SOIC-8 wide body for reinforced isolation and the SOIC-8 narrow for standard isolation. The driver's source and sink 5 A of current are designed for driving silicon carbide (SiC) MOSFETs. The driver chips support undervoltage lockout, an important requirement when driving SiC MOSFETs.
The driver chips are offered with a split output, allowing designers to use external gate resistors for pull-up or pull-down adjustments. The split output and compatibility with resistor pulls eliminate the need for external diodes, reducing cost and improving reliability. Isolation is also a critical component of power electronics in the KW regime. The MCP14C1 uses internal capacitive isolation, which reduces noise and inhibits unintended triggering.
Power
Rounding out the set are AEC-Q100-qualified SiC power MOSFETs in D2PAK-7 XL surface-mount packages. Microchip offers a wide selection of SiC MOSFETs that fit into automotive-qualified onboard charging solutions. Due to the higher bandgap and better thermal breakdown characteristics of SiC, SiC MOSFETs deliver higher voltages and current capacities.
dsPIC MCU, MCP14C1 gate drivers, and SiC MOSFETs.
The D2PAK-7L XL package complements the device's SiC-related advantages by providing five parallel source sense leads. These leads increase current capacity and reduce switching losses.
DSP MCUs, Gate Drivers, and SiC MOSFETs
In a typical EV charging scenario, power is presented to the vehicle at one of many different AC or DC voltages and delivered at one of several current flows. EV onboard charging systems take that power from the cable and convert it into a form that can be accepted by the EV’s battery pack. Such a circuit requires intelligence and power drive capacity tuned to the specific design attributes of the battery pack.
DC-DC converter block diagram for an onboard charger.
Proper charging circuit design can have a major impact on automotive range, battery life, and EV customer satisfaction. Yet designing from scratch is an incredibly complex and difficult process. By equipping the design with in-house components, users of the Microchip solution can have greater assurance that their designs will work reliably in the field. The Microchip solution uses proven components that are compatible with each other.
Broad Functionality From One Solution
Microchip’s reference designs include complete charging solutions that can be easily adapted to fit a wide variety of onboard charging scenarios. In addition to demonstration applications, reference designs, and built-up reference boards, the solution includes development and simulation tools, multiple component options, and a dedicated support team.
All images used courtesy of Microchip.
Hi Duane,
Thanks for the insightful article on Microchip’s new OBC solution for EV chargers. It’s great to see how the dsPIC33C DSC, MCP14C1 gate driver, and SiC MOSFETs are integrated to streamline the design process for EV developers.
The dsPIC33C’s dual-core architecture and advanced signal processing enhance control and efficiency, while the MCP14C1’s flexibility and robust performance make it ideal for driving SiC MOSFETs. The SiC MOSFETs’ thermal management and voltage handling are impressive, promising efficient and reliable charging.
Microchip’s comprehensive approach, including reference designs and support tools, is a valuable resource for simplifying the development of reliable onboard chargers. This should significantly boost the performance and reliability of EV charging systems.