New Industry Products

Silicon Labs Boosts Wolfspeed’s Power Modules

March 10, 2021 by Antonio Anzaldua Jr.

Silicon Labs (SLabs) has incorporated new technology into Wolfspeed’s Wolfpack series to accelerate fast-charging development for electric vehicles (EVs).

Silicon Labs has been at the forefront of developing innovative semiconductors for smart homes, industrial, automotive, and data centers that incorporate wide bandgap materials to pull away from traditional silicon. Recently, Silicon Labs announced a couple of next-gen devices that are going to be added to a collection of discrete products with Wolfspeed.

 

Silicon Labs’ Gate Driver & Digital Isolator 

The Silicon Labs’ Si823Hx is an isolated, gate driver board solution that encompasses gate-driving technology, versatile for a number of different power applications. This two-channel isolated gate driver solution features a differential digital interface. A unique feature is that this gate driver is able to protect power modules and sustain high-switching frequencies that occur with high-power density solutions. 

 

Shown above is the simplified layout for the Si823Hx, which combines two isolated gate drivers into a single package with each channel containing a RF transmitter and receiver. Image used courtesy of Silicon Labs.
Shown above is the simplified layout for the Si823Hx, which combines two isolated gate drivers into a single package with each channel containing a RF transmitter and receiver. Image used courtesy of Silicon Labs.

 

The other SiC-based technology designed by SLabs is the Si88xx digital isolator with integrated fly-back topology based dc-dc converter. SLabs’ robust isolator allows for the main SiC-based board to communicate the power module’s operating temperature levels to the main controller. This device features an external transformer to provide up to 5 W of isolated power with a 24 V input supply, making it ideal for industrial, automation, programmable logic controllers (PLC), battery management systems, and motor control applications 

The Vice President and General Manager of Power Products at Silicon Labs, Brian Mirkin discussed how their products would help engineers reduce the complexity of high powered designs, “The Silicon Labs Si823Hx gate driver board is an efficient, high-performance solution designed to simplify the development of systems using power modules.” Both the gate driver and isolator are highly versatile but must be combined with other key components in order to form a complete functional system. 

 

SLab’s Technology Suited for Wolfspeed’s Power Modules

Wolfspeed’s silicon carbide MOSFET portfolio offers the industry’s lowest on-state resistances in a discrete package as well as low switching losses, enabling high efficiency and power density.

 

The Wolfpack power module’s substrate is cooled directly which allows for excellent thermal management between converter designs. Image used courtesy of Wolfspeed. 
The Wolfpack power module’s substrate is cooled directly which allows for excellent thermal management between converter designs. Image used courtesy of Wolfspeed

 

A current rating of up to 105A and a max drain-soruce voltage of 1200V, the latest Wolfpack Half-bridge module is well equipped for EV charging solutions. Wolfspeed’s design reference showcases testing and measurement guides as well as power loop layout recommendations. The Wolfpack power modules have low conduction losses due to the SiC-based MOSFETs, making it easy to integrate into existing EV charging stations. 

The partnership of Wolfspeed and SLabs has also yielded a way to provide a small, cost-effective on-board charging system for EVs. This solution is a 6.6 kW, high power density, bi-driectional on-board charger that will utilize 650V SiC MOSFETs to handle instances with high frequency switching. The charger offers solid thermal management thanks to the integrated heatsink design that will remove heat from the MOSFETs, external transformer, and inductors.

 

Wolfspeed envisions all applications that are heavily dominated by silicon solutions to be limited in future growth in comparison to their line of SiC-based technology. Image used courtesy of Wolfspeed.

 

Why place so much attention on fast-charging? Well even though the demand for EVs has grown exponentially over the last decade, consumers are still hesitant to switch over from fuel combustion to electric powered automotives. Mainly due to concerns over the frequency and duration of charging in order to travel longer distances. To address this idea, fast-charging has become a goal for developers. Manufacturers similar to Silicon Labs and Wolfspeed are looking forward at what high-powered devices can be implemented into the charging component of EVs. The bi-driectional on-board charger and Wolfpack gate driver are great advancements in accelerating fast-charging development.