The investment follows initial seed financing secured by the company in 2010 and 2011 from SDTI, a leading Danish seed investment fund. The round is lead by VF Venture, the venture arm of the Danish investment fund Vækstfonden. SDTI has opted to expand its involvement and participate in the round. Additionally, a group of private investors has joined the round.
The ICs are based on the company’s patented EXIMO technology that reduces power losses at typical listening levels by up to a factor of 10, compared to conventional class-D amplifiers.
EXIMO is a switching amplifier technology that utilizes a new output stage topology and an associated modulation and power management scheme to achieve very low power losses at any output power level. Previous competing attempts to reduce power losses have relied on some type of supply rail variation. However, that involves either a more complex and expensive power supply or a separate boost converter that increases power losses, thereby effectively reducing efficiency at higher power levels in order to gain some at lower levels.
In addition to the power loss advantage, EXIMO allows a reduction of the need for output filtering. Class-D amplifiers designed for medium to high power levels require large LC reconstruction filters. Merus Audio’s technology uses filter inductors with a size of only 1/5th of those used in conventional class-D solutions for the same output power. It also allows using small SMD type ceramic filter capacitors instead of large film capacitors. And in many cases the filter can even be omitted entirely where other class-D solutions require a filter.
The filter enables compact amplifier solutions and – in addition to BOM reduction – gives manufacturers freedom in designing modern applications that have tough space constraints. The technology does not impose any system alterations in the target application.
Merus Audio is initially targeting home audio products but will be able to address other audio applications as well, including