Intermediate-Frequency DAC Resampling for Low-Jitter Signal Output
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Solution Overview
Problem
Existing data converters introduce artifacts into signals, leading to signal degradation, and there is a need for a low-cost solution that maintains high-quality signal integrity.
Innovation Solution
A digital-to-analog converter (DAC) system utilizing a programmable integrated circuit, a two-stage resampler, and a clock, which includes a D Flip Flop and a pulse resampler with a raised-cosine filter, to perform delta-sigma modulation and reduce timing jitter and additive noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional data converters are used, then signal conversion is achieved, but artifacts are introduced into the signal causing degradation
Solution Approach 1:
The patent divides the resampling process into two distinct stages: a first-stage resampler that performs initial rate conversion, and a second-stage resampler that completes the conversion. This segmentation allows each stage to handle specific aspects of the conversion, reducing the introduction of artifacts compared to a single-stage converter while maintaining signal integrity.
Solution Approach 2:
The patent introduces an intermediate digital signal as a mediator between the input digital signal and the final analog output. This intermediate representation allows for controlled transformation through the two-stage resampler, enabling artifact reduction while preserving the essential signal characteristics throughout the conversion process.
2Ease of manufacture
If low-cost data converters are used, then cost is reduced, but signal quality deteriorates due to added artifacts
Solution Approach 1:
The patent replaces traditional hardware-based data conversion mechanisms with a programmable integrated circuit that implements delta-sigma modulation and two-stage resampling through software-defined logic. This substitution enables low-cost implementation while maintaining high signal quality, as the programmable approach allows for optimized artifact reduction algorithms without requiring expensive dedicated hardware.
Solution Approach 2:
The patent utilizes programmable parameters within the integrated circuit to dynamically adjust the modulation and resampling characteristics. By changing these parameters, the system can optimize performance for different signal conditions while maintaining cost-effectiveness, achieving high signal quality without the need for expensive fixed hardware designs.
3Device complexity
If single-stage resampling is used, then device complexity is reduced, but timing jitter and additive noise increase
Solution Approach 1:
The patent segments the resampling function into two distinct stages, where the first-stage resampler handles the initial frequency conversion and the second-stage resampler completes the process. This segmentation distributes the timing precision requirements across both stages, reducing the timing jitter and additive noise that would occur in a single-stage design, while maintaining manageable device complexity through modular architecture.
Data Source
AI summary
The present disclosure describes a digital-to-analog converter (DAC) comprising a programmable integrated circuit, a resampler, and a clock. The programmable integrated circuit may be configured to perform delta-sigma modulation to convert a digital signal to a coarse representation of an analog signal. The coarse representation of the analog signal may be sent to a first-stage of the resampler. After processing the signal, the first-stage of the resampler may pass a continuous signal to the second-stage of the resampler. The second-stage of the resampler produce a clean sampling instant for the signal that represents the point in time where the signal transitions from discrete time to continuous time. The analog signal may then be outputted to one or more receivers.