Power Amplifier Driver DAC with On-Chip Quantization Noise Filtering
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Solution Overview
Problem
Conventional mobile multimedia processors face challenges in fully utilizing system-on-a-chip integration for advanced total system solutions, leading to increased power consumption, implementation complexity, and terminal size, while also introducing quantization noise during digital to analog conversion in polar modulation systems.
Innovation Solution
A method and system for digital to analog conversion in a single integrated circuit device that enables amplitude control for power amplifier drivers, utilizing oversampling and delta sigma modulation to filter quantization noise and integrate low pass filter circuitry within the chip, thereby reducing power consumption and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital to analog conversion is performed in conventional polar modulation systems, then signal representation is converted from I-Q to magnitude-phase components, but quantization noise is introduced during the conversion process
Solution Approach 1:
A dither signal is introduced as an intermediary element between the digital signal and the quantization process. This dither signal masks the quantization noise by adding random variations that spread the noise energy across a wider frequency spectrum, thereby reducing the perceived quantization noise in the signal band while maintaining conversion accuracy.
2Object-generated harmful factors
If filtering circuitry is located off-chip as a discrete component, then quantization noise can be filtered, but device complexity and terminal size increase
Solution Approach 1:
The filtering circuitry is merged with the digital to analog conversion circuitry into a single integrated chip. The low-pass filter is designed to work in conjunction with the dither signal generation and quantization process, combining multiple functions (conversion, dithering, and filtering) into one unified device, thereby reducing system complexity and terminal size while maintaining noise filtering capability.
3Productivity
If multiple hardware accelerators are utilized for multimedia applications, then processing capabilities are enhanced, but power consumption and implementation complexity significantly increase
Solution Approach 1:
The integrated circuit is designed to perform multiple functions including digital to analog conversion, dither signal generation, filtering, and support for various modulation schemes (QPSK, 8-PSK, 16-QAM, etc.). This multi-functional design eliminates the need for separate hardware accelerators for different multimedia applications, reducing power consumption and implementation complexity while maintaining enhanced processing capabilities.
Data Source
AI summary
Aspects of a method and system for digital to analog conversion for power amplifier driver amplitude modulation are presented. Various aspects of the system may include circuitry that enables oversampling, within a single integrated circuit device, of each of a plurality of samples in a digital baseband signal. The circuitry may enable reduction of a number of bits, i.e., coarse quantization, in each of the oversampled plurality of samples so as to cause displacement of the quantization noise that occurred as a result of the coarse quantization. A subsequent signal may be generated based on the oversampled signal. The circuitry may enable the subsequent signal to be low-pass filtered utilizing filter circuitry in the single integrated circuit device, thereby attenuating the quantization noise displaced into the higher frequency range of the oversampled signal.