Sarda Technologies (see 3/12 profile) was founded in late 2010 to develop power semiconductors for DC-DC voltage converters for portable, enterprise and consumer systems. The company was targeting the smartphone and mobile PC markets, but has pivoted to the datacenter market. Sarda has raised roughly $5 million to date from IDEA Fund Partners, Terracap Ventures, and Qorvo. The company is now raised a $5-15M funding round. Sarda has 5employees and will be scaling up after it closes its round.
Sarda’s technology results from a radical reimaging of the basic field effect transistor geometry, which enables the switches used in converters to achieve ultra low power loss and very high switching frequencies. Sarda was awarded an NC IDEA grant in the Spring of 2011, receiving funds to assist in the patenting of its technology. The company has 14 issued US patents.
Silicon-based power switching technology currently utilized in DC-DC converters is not highly efficient. Sarda replaces the incumbent silicon switches used in switched-mode voltage regulators with Gallium Arsenide (GaAs) switches. Sarda argues that GaAs is the perfect technology for DC-DC voltage converters, providing superior efficiency and competitive cost structure, piggybacking off the enormous GaAs PA handset market. Sarda’s patented technology reduces the GaAs die size and cost by 80%, bringing the benefits of GaAs to voltage regulators.
The electron mobility of GaAs is 5-6X higher than silicon MOSFETs and Gallium Nitride (GaN) FETs, resulting is much lower switching losses. Monolithic integration of multiple switches minimizes parasitic losses. Other benefits include very low gate and output charge, and zero source-drain recovery charge. GaAs also benefits from high temperature operation resulting from its higher bandgap and high reliability resulting from its high activation energy and no gate oxide.
To fully capture the benefits of it’s GaAs FETs, Sarda’s Heterogeneously Integrated Power Stages (HIPS) combines GaAs for the switches and CMOS for the drivers and protection. An embedded die SiP integrates the components required for high efficiency at high switching frequency in a standard package with a 5x5mm footprint, 1mm height and standard interface to third-party controllers. Due to its higher switching frequency, HIPS significantly reduces the size of the inductor and capacitors used in the voltage regulator’s power train.
HIPS increase voltage regulator speed by 10x. This enables granular power delivery, which reduces system energy consumption by 30%. For each load, granular power provides faster transition to idle modes and lower voltage setpoint, enabling higher idle mode efficiency. It also provides faster transition to peak modes and higher voltage setpoint. The small solution size also frees up board space.
Sarda believe it is targeting a $1 billion market opportunity, comprised of 12V intermediate bus converters. Currently, competitor comes from incumbent silicon technologies, such as slow lateral MOSFETS, which have bad overshoot, limiting performance and efficiency. Competing GaAs and GaN alternatives have large die sizes and unique drive requirements.
Lateral MOSFETS typically support output currents under 5A. Vertical MOSFETS, GaN FETs and SiC FETs can support higher output currents, and voltages, but can not achieve as high a switching frequency as GaAs. RDS(on)*QG FOM (mohm‐nC) for Sarda’s GaAs FETs is 12, moving to 3, which is 10-20X better than GaN-on silicon FETs or vertical MOSFETs.
Qorvo (TriQuint) is supporting Sarda for the GaAs die using a 0.25-0.5u process. Sarda’s driver is currently being fabricated in ams’ 0.35µm high-voltage CMOS specialty process, which allows the efficient integration of voltage domains ranging from 3V to 120V on a single monolithic IC.
Sarda’s first products target 12V input voltage regulators that use miniature inductors, and provide two phases or independent outputs, output up to 20A and support up to 5MHz switching frequency. Follow-on products will increase the input voltage, output current and switching frequency.
Evaluation boards are available now featuring 12V input, 1V / 14A output, and 4Mhz switching frequency with roughly 85% efficiency. The next HIPS revision will be released this summer, featuring a smaller package size, higher switching frequency, higher efficiency (>90%), and higher current output.
Sarda is currently engaged with industry leaders in the processor and server markets.
Bob Conner, CEO and Co-Founder (previously CEO & founder of Symmorphix, an Applied Materials spinout, VP Photovoltaics at Semprius, VP marketing and business development at Nextreme, and VP and product manager, respectively, at Cirrus Logic and Chips and Technologies)
Greg Miller, SVP of Engineering (previously VP of Applications Engineering and Power Management Architectures at Intersil)
Jim Vorhaus, Ph.D., Co-Founder (previously held numerous positions in the compound semiconductor MMIC field, including COO of Nitronix)