1-Bit DAC Clock Recovery to Prevent RF Transition Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
1-bit digital-to-analog converters can introduce or exacerbate waveform distortion in transition periods, affecting the quality of RF signals, particularly when used in conjunction with delta-sigma modulators.
Innovation Solution
A 1-bit digital-to-analog converter that includes a clock and data recovery circuit to generate a recovered clock and recovery signal, with a switch controlling an analog pulse train to be intermittent based on the recovery signal, thereby generating an analog pulse signal that is not affected by distortion in transition periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a 1-bit digital-to-analog converter is used to convert quantized signals from a delta-sigma modulator, then the device complexity is reduced and ease of manufacture is improved, but waveform distortion occurs in transition periods causing degradation of RF signal quality
Solution Approach 1:
The patent introduces an intermediary processing stage between the delta-sigma modulator and the 1-bit DAC. A waveform correction circuit processes the quantized signal to correct asymmetric waveform distortion before it reaches the DAC, thereby maintaining signal quality while using a simple 1-bit converter structure
Solution Approach 2:
The patent applies preliminary waveform correction to the quantized signal before it enters the 1-bit DAC. By pre-correcting the asymmetric rising and falling waveforms in the digital domain, the system prevents distortion from propagating to the analog output, thereby maintaining high signal quality with a simple converter
2Manufacturing precision
If the waveform of the pulse signal after delta-sigma modulation is corrected to maintain symmetry, then the signal quality is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex analog waveform correction circuits with a digital signal processing approach. The waveform correction is performed in the digital domain using simple logic operations on the quantized signal, avoiding the need for complex analog components while maintaining signal quality
Solution Approach 2:
The patent changes the approach from correcting waveform shape parameters in the analog domain to adjusting digital signal parameters in the quantized domain. By modifying the digital representation of the signal before conversion, the system achieves waveform correction with minimal additional complexity
Data Source
AI summary
A 1-bit digital-to-analog converter includes a clock and data recovery circuit configured to output a recovered clock signal and a recovery signal, based on a 1-bit digital input signal; and a switch to which an analog pulse train based on the recovered clock signal is given. The switch is on/off controlled by the recovery signal, and outputs an analog pulse signal in which the analog pulse train is made intermittent according to the recovery signal.