DAC Voltage Shift Compensation for Linearity and Output Range
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Solution Overview
Problem
Existing digital-to-analog converters (DACs) face challenges in adjusting conversion linearity and output range due to variations in internal components and limitations imposed by reference voltage.
Innovation Solution
The DAC incorporates first and second operational amplifiers, resistor circuits, and voltage shift circuits to adjust conversion linearity by providing compensation voltages to their inverting input terminals, allowing for calibration of output range and improved flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the reference voltage is used to limit the output range of the DAC, then the output range is constrained, but the conversion linearity cannot be adjusted
Solution Approach 1:
The patent divides the voltage compensation function into two separate operational amplifiers (OPA1 and OPA2), each handling different aspects of voltage adjustment. This segmentation allows independent optimization of output range and conversion linearity without mutual interference, resolving the technical contradiction between adaptability and manufacturing precision.
Solution Approach 2:
The patent introduces compensation voltages (VC1 and VC2) as intermediary signals that mediate between the reference voltage and the DAC output. These compensation voltages allow dynamic adjustment of the output range while maintaining conversion linearity, effectively decoupling the two previously coupled parameters.
2Manufacturing precision
If the internal components of the DAC are varied due to process differences, then the conversion linearity varies, but the output range remains limited by reference voltage
Solution Approach 1:
The patent implements a feedback mechanism where the compensation voltages VC1 and VC2 are dynamically adjusted based on the actual output of the DAC. This feedback loop compensates for process-induced variations in internal components, maintaining consistent conversion linearity across different manufacturing batches while allowing flexible output range adjustment.
Solution Approach 2:
The patent changes the voltage parameters (compensation voltages VC1 and VC2) to compensate for process variations in internal components. By dynamically adjusting these voltage parameters, the system maintains stable conversion linearity despite manufacturing variations, while simultaneously enabling flexible output range control.
3Manufacturing precision
If compensation voltages are provided to adjust conversion linearity, then the conversion linearity improves, but the device complexity increases
Solution Approach 1:
The operational amplifiers OPA1 and OPA2 serve multiple functions: they generate compensation voltages for linearity correction, adjust the output range, and provide feedback control. This multi-functionality reduces the need for separate dedicated circuits, thereby limiting the increase in device complexity while achieving improved conversion linearity.
Data Source
AI summary
A digital-to-analog converter (DAC) and an operation method thereof are provided. The DAC includes a first operational amplifier (OPA), a second OPA, a resistor circuit, first switches, second switches, a first voltage shift circuit and a second voltage shift circuit. The first OPA outputs a first operating voltage. The second OPA outputs a second operating voltage. First terminals of the first switches receive the first operating voltage. First terminals of the second switches receive the second operating voltage. Second terminals of the first switches and the second switches are coupled to the resistor circuit. The first switches and the second switches perform switching operations in response to digital values. The first voltage shift circuit provides a first compensation voltage to the first OPA. The second voltage shift circuit provides a second compensation voltage to the second OPA.