A/D Converter Delay Cell Bias Current Temperature Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional A/D converters using delay cells face issues with temperature-induced variations in delay time, leading to unstable output voltage in power supply circuits due to changes in signal propagation delay, which affects the accuracy of digital output signals.
Innovation Solution
The proposed A/D converter employs two delay cell columns with bias currents corresponding to difference voltages, encoding the difference in delay time between these columns to maintain a stable digital output, using a detection signal generation circuit to cancel out temperature-induced variations in signal propagation speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a delay line A/D converter uses a delay cell column biased by a reference voltage as a reference, then the A/D conversion can be performed, but the output signal varies due to temperature-induced changes in delay time
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the bias current supplied to the reference delay cell column based on detected delay time variations. When temperature changes cause delay time variations, the bias current is modified to compensate for these changes, thereby maintaining stable output signals and reliable A/D conversion accuracy across different operating conditions
Solution Approach 2:
The patent implements a feedback mechanism where the delay time of the reference delay cell column is continuously detected, and this detection information is used to adjust the bias current. This closed-loop feedback system ensures that variations in delay time due to temperature changes are compensated, maintaining both measurement precision and output signal stability
2Speed
If the delay time of delay cells changes due to temperature, then the signal propagation delay varies, but this causes the output voltage of power supply circuits to vary
Solution Approach 1:
The patent compensates for temperature-induced signal propagation speed variations by dynamically changing the bias current parameter in the reference delay cell column. This parameter adjustment counteracts the effects of temperature changes on signal propagation, thereby maintaining stable output voltage in power supply circuits despite variations in signal speed
Solution Approach 2:
A feedback loop is established where signal propagation delay is detected and used to adjust the bias current in real-time. This feedback mechanism ensures that changes in signal propagation speed due to temperature are compensated, maintaining output voltage stability
Data Source
AI summary
According to one embodiment, an A/D converter includes a first delay cell column in which a plurality of delay cells, to which a first bias current corresponding to a difference voltage between an input voltage and a reference voltage is supplied, is connected in series. The converter includes a second delay cell column in which a plurality of delay cells, to which a second bias current corresponding to a negative-phase difference voltage of the difference voltage is supplied, is connected in series. The converter includes an encoder unit configured to encode a difference value, in delay time of signal propagation, between the first delay cell column and the second delay cell column.