Switched-Capacitor DAC Reference Circuit for Low Noise and Power
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Solution Overview
Problem
Digital-to-analog converter (DAC) circuits in modern communication devices face challenges in low power consumption and noise performance, particularly in high dynamic range applications, which affect battery life and communication reliability.
Innovation Solution
A low noise, low power consumption digital-to-analog converter reference circuit is implemented using a reservoir capacitor to reduce the need for resistive elements, minimizing power consumption and noise injection, while maintaining high dynamic range capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional DAC reference circuits are used to achieve high speed linear operation, then conversion speed and linearity are improved, but power consumption increases significantly
Solution Approach 1:
The patent extracts and eliminates resistive elements from the DAC reference circuit, replacing them with a switched capacitor architecture. This removal of resistors directly reduces power consumption while maintaining the high-speed conversion capability through capacitive switching operations that do not require continuous power dissipation.
Solution Approach 2:
The patent substitutes the traditional resistive (ohmic) system with a capacitive switching system. Instead of using resistors to set reference voltages and currents, the invention uses capacitors controlled by switches, fundamentally changing the mechanism from resistive voltage division to capacitive charge transfer, thereby eliminating continuous power consumption.
2Measurement precision
If traditional DAC reference circuits with resistive elements are used, then conversion accuracy is maintained, but noise performance deteriorates
Solution Approach 1:
The patent removes resistive elements that generate thermal noise from the circuit. By eliminating resistors from the reference circuit architecture, the primary source of noise is extracted and removed, thereby improving the signal-to-noise ratio while preserving conversion accuracy through the noise-free capacitive switching mechanism.
3Device complexity
If resistive elements are used in DAC reference circuits, then circuit functionality is simplified, but power consumption and noise increase
Solution Approach 1:
The patent replaces the resistive mechanism with a capacitive switching mechanism. The switched capacitor reference circuit uses capacitors and switches to perform the same reference voltage generation function as traditional resistive circuits, but without the continuous power consumption and noise associated with resistive elements. The functionality is maintained through periodic charge transfer operations.
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
The solution effectively reduces power consumption and noise floor, allowing for high dynamic range DAC operation without increasing resistor capacitor time constants, thereby enhancing battery life and communication reliability.
Implementation Method 1
A low noise, low power consumption digital-to-analog converter reference circuit is implemented using a reservoir capacitor to reduce the need for resistive elements
Data Source
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AI summary
The present patent application comprises a digital to analog converter reference circuit, comprising a capacitor connected to a current source, a positive terminal of the capacitor connected to a first switch, the first switch electrically connecting the positive terminal of the capacitor to a positive input terminal of a DAC circuit, a negative terminal of the capacitor connected to a second switch, the second switch electrically connecting the negative terminal of the capacitor to a negative input terminal of the DAC circuit. In another example, the present patent application comprises a method for converting digital code to an analog signal, comprising charging a reservoir capacitor to a reference voltage level, transferring stored charge from the reservoir capacitor to DAC feedback capacitors, and transferring the stored charge from the DAC feedback capacitors to DAC output terminals.