Demand for more efficient power solutions continues to grow in applications from home appliances and power tools to renewable energy and electric vehicles (EVs). Qorvo’s power products bring new levels of efficiency to a wide range of automotive, commercial, industrial and consumer applications. Leveraging the acquisitions of Active-Semi and UnitedSiC has given Qorvo the power technologies to meet the world’s growing power needs.

Active-Semi brings highly configurable power application controllers (PACs) and programmable analog power management integrated circuits (PMICs) to minimize energy usage, reduce solution size and cost, improve system reliability and shorten system development time.

UnitedSiC devices deliver superior performance in high voltage switched mode power conversion and circuit protection applications enabled by advanced silicon carbide (SiC) wide bandgap semiconductor technology. Important SiC technology figures of merit (FoM) enable better SiC field-effect transistors (FET) product performance, resulting in optimal power solutions in leading-edge designs for high growth markets.

Strong power foundation

Qorvo has been developing compound semiconductors like gallium nitride (GaN) and gallium arsenide (GaAs) for RF power, but through strategic acquisitions, has now added SiC power semiconductor and power management devices to its portfolio.

Qorvo’s power management capabilities range from analog power such as DC/DC converters and PMICs, to digital motor control and battery management solutions. While these have been focused on consumer and industrial applications less than 3 kW, the SiC devices extend the portfolio to address higher power levels. Together, these products create complementary power solutions where the power management devices can drive SiC power FETs, extracting optimal device performance, while also offering the potential for diagnostic features like temperature and current monitoring. These offerings allow Qorvo to serve three industry power pillars: SiC power, intelligent motor control and PMICs.

SiC power

The power semiconductor landscape has traditionally been dominated by silicon-based power diodes and transistors such as insulated gate bipolar transistors (IGBTs) and super junction metal oxide semiconductor FETs (MOSFETs). The technological maturity and cost-effectiveness allowed these devices to dominate applications across the power spectrum, from cordless power tools to EV charging and electric railway use cases. However, SiC’s advantages in the high voltage realm (greater than 650 V) allow for improvements in efficiency and power density demanded in applications including EVs, IT infrastructure, renewable energy and battery charging. SiC’s better electrical breakdown characteristics allow the realization of FETs with lower on-resistance and lower device capacitance; both help minimize the power losses encountered during operation, thus boosting the system efficiency.

Figure 1. The power semiconductor landscape. Source: Qorvo

Many power companies are expanding their SiC fabrication efforts to meet growing demand while delivering cost and performance optimized technology. To meet these demands, the power transistor must have a low ‘on-state resistance times area’ figure-of-merit (or R*A FoM), allowing for a reduction in both conduction and switching power losses and an increase in efficiency — factors that miniaturize the design and simplify the system’s thermal management while keeping costs low. A low R*A FoM for the power device brings high frequency operation and improved converter efficiency in both hard- and soft-switched power converter circuits.

Qorvo now offers a lineup of Gen 4 750 V and 1,200 V SiC FETs with the industry's best R*A FoM of less than 1.5 mohm-cm2 (at 125° C, for 750 V class of devices) which is two times lower than 650 V SiC MOSFETs. The low R*A FoM allows about twice the number of chips per wafer — a significant advantage in volume manufacturing. Included in this Gen 4 series is the UJ4SC075006K4S, a 750 V SiC FET with the industry’s lowest RDS(on) at 6 milliohms. The series includes multiple on-resistance values and package combinations, enabling more design flexibility that delivers the optimum cost-efficient power design. The simple 0-12 V, 0-15 V gate drives are also compatible with all SiC MOSFET, Si MOSFET and Si IGBT drive voltages for easy design-in.

Figure 2. A SiC MOSFET (left) and the Qorvo JFET "cascode" circuit configuration (middle). Source: Qorvo

Intelligent motor control

To take advantage of the benefits of next-gen power devices, pairing them with optimized controller solutions is critical. This is broken down into two main areas: motor control and power management.

Qorvo has introduced a range of PAC; system-on-chip (SoC) devices that can implement brushless DC motor (BLDC) or permanent magnet synchronous motor (PMSM) programmable motor control and driver functionality in a single IC.

Figure 3. Application circuit with PAC device. Source: Qorvo

The scalable platform integrates an MCU and application-specific power and analog peripherals for high configurability. The SoCs combine three high- and low-side gate drivers with up to a 12-bit analog-to-digital converter (ADC) and sequencer as well as a highly configurable analog front-end power regulator. This results in smaller size, higher reliability and lower BOM cost with component reduction in both AC- and battery-powered applications. Reference designs are available; the RD5556SiC showcases Qorvo’s PAC5556A motor controller and SiC FET cascode power switches. The design can be used for three-phase motor control up to 600 V DC and 6 kW, as is found in AC appliances, for example.

Figure 4. Qorvo motor control ICs. Source: Qorvo

PMICs

With every design, engineers must map out their system-level power tree to define a power solution that meets specific power requirements and optimizes efficiency, power dissipation, battery life, cost and system size. This is achieved by designing each circuit in-house but requires a high degree of complexity. There are multiple converter topologies available on the market used to implement a voltage rail. Still, devices like field-programmable gate arrays, digital signal processors and ADCs require the supply voltages to be powered up and down in sequence; a process that can be programmed but comes with considerations that often require an additional MCU.

This is where PMICs offer an alternative; a fully integrated cost-effective solution that implements all the system rails with few external components. The drawback of many PMICs is relative inflexibility, reducing their utility to a narrow set of operating conditions. Qorvo offers a family of PMICs with multi-time programmable ActiveCiPS technology. This allows designers to change the various PMIC settings in the lab without changing external components, thus reducing design risk and accelerating time to market. The high configurability and flexibility of the Qorvo PMICs enables designers to leverage the same silicon for different end-market applications on different SKUs, which eases design and material management, and reduces cost.

Figure 5. Visual representation of space savings. Source: Qorvo

Qorvo PMICs such as the ACT88760 come with an evaluation kit, programming dongle and a graphical user interface (GUI), allowing users to program new settings into non-volatile cells inside the PMIC for application customization. Every switcher block within the PMIC needs only three external components to operate: an input capacitor, output capacitor and a small inductor. If more rails are needed, the design can be added to an external DC/DC and sequenced using one of the PMIC’s general-purpose input/output pins.

Conclusion

Over multiple decades, Qorvo has built and delivered the industry's best RF products. With the addition of SiC switch mode power transistors Qorvo is strengthening its leadership position in the area of compound semiconductors.

Further, Qorvo’s offerings in gigahertz-range RF power is now nicely complemented by the addition of power management controllers and SiC power FETs operating in tens-to-hundreds of kilohertz in traditional switch mode power electronics, offering cutting-edge solutions for applications in all parts of the power spectrum. To learn more about Qorvo’s power offerings, visit their website.