Many circuit techniques are presently under development. The following are patented or patent-pending technologies being developed by Acutechnology:
1. The Orthophase™ inductor technology provides a means for implementing high power, high frequency inductors within a PC board without the EMI concerns of typical air-core techniques. Orthophase™ technology allows the inductor to be implemented directly in a printed circuit, eliminating the ferrite core and its losses, and reducing the height of the power circuitry.
[US patent 7,221,251]
2. The QuikLDO™ is an improved architecture for CMOS LDOs allowing for high speed and low dropout without requiring load capacitance for stability. A capless LDO saves board space and improves load transient performance.
[US patent 6,989,659]
3. AcuRef™ voltage reference technology allows for a greatly reduced process sensitivity in bandgap references used in our products. Using the relationship between transistor beta and Vbe, the reference is given a beta dependent term that cancels the beta dependence of the reference. This allows for higher precision products to be made without requiring trimmed bandgaps, or much simpler trimming to reach a given precision.
[US patent 7,071,673]
4. The CasPump™ converter technology allows for the primary side control of a switching regulator to operate without an auxiliary rail or bias winding. By recirculating energy from the gate drive, a significant power savings can be made.
5. Sigma-Servo™ technology allows for both improved performance and reduced cost in servosystems for motor control by replacing conventional D/A converters with oversampling modulators to create high frequency bitstreams rather than continuous analog control signals. This technique eliminates noise and distortion due to DAC nonlinearity and allows for much simpler implementation of very high resolution systems.
[US patent 7,034,490]
6. The MirrDrive™ technology allows for digital motor control with zero offset and lower noise. By forcing the motor current directly, the need for a current sense amplifier, with its noise and bandwidth limitations, is completely eliminated. The MirrDriv™ technology cuts the system complexity of a precision DC servomotor control loop.
[US patent 7,224,135]
We are presently working with our vendors to generate innovative new packaging solutions. The first such innovation is the TetraPack™ , a four terminal package that fits precisely in a standard SOT-223 footprint. We are also working on innovative strategies for reducing the cost of analog testing at wafer sort and for packaged parts.
Acutechnology is working with our fab partners on generation of well optimized power processes. It is our intention to develop foundry processes that can be competitive with the best of the proprietary power processes. To those familiar with digital wafer foundries, this may seem an obvious statement, but processes that are well optimized for power are generally unavailable from foundries. We are particularly pleased to be working on a fine BCD (bipolar/CMOS/DMOS)technology that bridges a major gap in the offerings of standard foundries.
Acutechnology has ongoing R&D efforts in several areas. Although most development work is proprietary, some of the research into the known art is generally useful and not indicative of sensitive ongoing development work. One such areas is the patent research we have undertaken in the areas of Class D Audio amplifiers and in aspects of power IC development:
Class D Audio - We have compiled a reasonable database in the area of switching amplifier patents as well as other literature that defines the "prior art" in this area. Most new patents are a continual re-invention or very minor improvement on forty years of prior art.
Power IC Barrier Structures - The use of large switching power transistors on a monolithic IC creates severe problems with parasitic devices and with substrate-coupled noise. It is usual to put a "barrier" between the power device and any sensitive circuitry. We have generated a brief historical review of Barrier patents, which indicate that the key patents on which most solutions are built are now expired.