Introduction

The current fast charging industry chain has evolved from traditional silicon MOS to super junction MOS, and in the past decade, gallium nitride (GaN) has become widely adopted in 60W, 100W, and 140W adapters. Each innovation at the device level has rewritten the balance between power density, efficiency, and cost. Now, as USB PD3.1 pushes the adapter power limit to 140W and beyond, the challenge is how to meet high power, high efficiency, low standby loss, and stringent energy efficiency standards within limited size and cost budgets, which has become a new proposition for the industry.

Recently, from a teardown, it was learned that Renesas has launched a 140W silicon carbide fast charging reference design. This solution deeply integrates single-stage PFC with silicon carbide power devices, accomplishing the roles traditionally handled by a silicon carbide diode, a PFC GaN switch, and two main power GaN switches, stacking higher power density and stronger cost-performance ratio with fewer devices. Next, we will provide a detailed introduction.

Renesas 140W Silicon Carbide Fast Charging Reference Design

The core of Renesas’ 140W silicon carbide fast charging reference design is the iW3627-00, a single-stage high power factor AC/DC constant voltage controller, which combines PFC power factor correction and energy conversion in a single-stage architecture, eliminating redundant loops between the PFC stage and the main power stage found in traditional “two-stage” solutions. Thanks to this single-stage architecture, the system directly eliminates the bulky independent PFC boost inductor and inter-stage high-voltage capacitors found in traditional high-power solutions, significantly reducing PCB footprint and noticeably shrinking the overall size of the adapter, achieving a more extreme miniaturized design.

Correspondingly, by introducing a high-voltage, high-speed silicon carbide power device, the current paths and switching responsibilities originally distributed across a silicon carbide diode, a PFC GaN device, and two main power GaN devices can be concentrated onto a single high-performance SiC switch.

Next, let’s briefly discuss the chips used in this solution.

Primary Control Chip Renesas iW3627-00

The Renesas iW3627-00 is a single-stage AC/DC constant voltage controller with power factor correction capabilities, supporting both isolated and non-isolated topologies, achieving extremely low load and line voltage adjustment rates without the need for secondary feedback circuits. The chip does not require external loop compensation components and comes in a SOT23 package.

This solution is paired with a silicon carbide switch rated for 800V and a conduction resistance of 165mΩ. Thanks to the high voltage margin, low reverse recovery loss, and high-frequency switching capability of SiC devices, it can maintain efficiency and thermal design under high line voltage and high power conditions, further reducing the number of devices in the main power stage and alleviating thermal stress..

Synchronous Rectification Controller Renesas iW610-01C

In this reference design, in addition to the iW3627-00, the iW610-01C is also present on the secondary side, responsible for high-efficiency synchronous rectification control.

The Renesas iW610-01C synchronous rectification controller supports QR, ZVS, ACF, and LLC switch power supply applications. The chip supports DCM and CCM operating modes, low-side and high-side applications, and a 3-28V output voltage range, packaged in a SOT23 format.

For this 140W fast charging reference design, it provides robust efficiency support for the high power output stage and reserves sufficient energy efficiency space for subsequent multi-channel DC-DC buck conversion, ensuring that the entire system maintains a high overall efficiency curve during single-port 140W and multi-port distribution outputs.

Summary from Charging Head Network

Renesas’ silicon carbide 140W fast charging reference design primarily utilizes the primary control chip iW3627-00 paired with the synchronous rectification controller iW610-01C. This solution has very clear technical labels, primarily targeting USB PD3.1 scenarios, achieving a deep integration of single-stage PFC + SiC in the adapter power segment, and more importantly, under the coordination of Renesas’ power architecture, a single SiC device completes the functions traditionally handled by diodes and GaN switches in the system level, achieving a true “device subtraction, system optimization” approach, finding a new balance between power density, efficiency, and cost.

The significance of this reference design goes beyond just adding another 140W solution option. On one hand, it brings SiC from high-voltage industrial applications into the fast charging adapter field, allowing the advantages of silicon carbide to be more widely validated and scaled in the 100W+ power segment; on the other hand, it provides a valuable reference for the entire fast charging industry through its single-stage PFC architecture and system-level simplification, moving complexity from hardware to architecture and algorithm levels, establishing a more efficient and cost-effective system with fewer devices.