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DDX® Technology

Direct Digital Amplification (DDX®) is a patented Apogee Technology Inc. tool. It provides an all-digital, high-efficiency amplification technology used in a wide range of consumer audio products (further information from Apogee at www.apogeeddx.com).


DDX® converts digital audio directly into power without the need of a digital-to-analog converter (DAC). Embedded signal processing is used to convert digital data into Apogee's patented damped ternary modulation to directly control power-switching devices. The output is filtered to remove high frequency to produce the audio signal for speakers. This approach allows digital audio sources such as CDs, DVDs, DTVs to remain digital from source to the speakers, eliminating analog signal corruption.

 
ddx
DDX® High Efficiency Amplifier Technology
 
Conventional Class D Amplification
Damped Ternary Modulation

Conventional Class D amplifiers utilize binary, or BI-state operation. Binary consists of only two switching states, positive power and negative power. Damped Ternary Modulation consists of three switching states; positive, negative and a zero power state. During the time when neither supply connection is required, both speaker terminals are connected to each other providing damping to the loudspeaker.
Damped Ternary Modulation

The figure shows the advantage of the damped ternary compared to binary modulation for a sine wave. In binary the cancellation of two full level signals is required for small outputs. Thus, the amplifier is continuously providing full output. This represents wasted power. It also produces unwanted RF energy that must be kept from radiating. In contrast damped ternary only supplies power to produce a signal.