Continuous-Time DAC Deglitching Circuit for Glitch and Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional deglitching techniques for digital-to-analog converters (DACs) suffer from issues such as capacitive discharge and noise introduction due to the use of switches and operational amplifiers, which result in glitches and noise in the analog output.
Innovation Solution
A continuous-time deglitching technique that eliminates the need for a switch by using a differential current output DAC and an operational amplifier to track and match the voltage potential of both DAC outputs, reducing transient voltages and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a switch is used to isolate the DAC output from the Op Amp during transitions, then glitches can be prevented from affecting the analog output signal, but charge-injection due to the operation of the switch is still present causing glitches at the input of the Op Amp
Solution Approach 1:
The patent removes the switching component entirely from the circuit architecture. By using a continuous-time deglitching approach with buffered differential outputs, the invention extracts the harmful switching function and replaces it with a continuous operation mode, eliminating charge-injection effects at the source.
Solution Approach 2:
The invention implements continuous-time deglitching by maintaining continuous buffering of both differential outputs throughout the conversion process. This continuous operation eliminates the discontinuous switching action that causes charge-injection, ensuring smooth transitions without harmful transient effects.
2Reliability
If an operational amplifier is used to buffer the DAC output, then the analog output signal can be maintained, but the Op Amp may introduce noise at the output
Solution Approach 1:
The patent extracts and removes the noisy operational amplifier from the signal path. By implementing direct buffered differential outputs without Op Amps, the invention eliminates the noise source while maintaining signal stability through alternative buffering architecture.
3Object-affected harmful factors
If a sample and hold circuit is implemented to smooth DAC output, then glitches can be reduced, but the circuit complexity increases with additional components
Solution Approach 1:
The patent merges the deglitching function directly into the DAC output stage by implementing continuous-time deglitching with buffered differential outputs. This integration eliminates the need for separate sample and hold circuits, reducing overall circuit complexity while maintaining glitch reduction performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes voltage differences during switching and suppresses charge sharing, effectively eliminating glitches and noise in the DAC output, improving the stability and accuracy of the analog signal.
Implementation Method 1
The operational amplifier is configured to operate the transistor to adjust the voltage potential of the second output to substantially match the voltage potential of the first output
Implementation Method 2
a transistor coupled to the second output and the output of the operational amplifier. The operational amplifier is configured to operate the transistor to adjust the voltage potential
Data Source
AI summary
A processor and a circuit implementing a continuous-time deglitching technique for a digital-to-analog converter are disclosed. The circuit includes a digital-to-analog converter having a differential current output, an operational amplifier having an inverting input coupled to a first output of the differential current output and a non-inverting input coupled to a second output of the differential current output, and a transistor coupled to the second output and the output of the operational amplifier. The operational amplifier is configured to operate the transistor to adjust the voltage potential of the second output to substantially match the voltage potential of the first output.