Adaptive Sample-and-Hold Circuit for Seamless Amplifier Range Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-level Class D amplifiers face increased design complexity and reduced efficiency due to the need for seamless step changes in modulation levels when switching between supply voltage ranges, which is typically handled by the modulator, leading to disturbances in the loop.
Innovation Solution
An adaptive sample and hold circuit that includes a range detector to identify signal ranges and adjust the sample-and-hold-voltage, maintaining it within a predetermined voltage span by switching between multiple voltages, thereby simplifying the modulation process and reducing design complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the modulator handles step changes in modulation levels when switching between supply voltage ranges, then the amplifier can operate across multiple voltage ranges, but the design complexity increases and efficiency decreases due to loop disturbances
Solution Approach 1:
The patent extracts the range detection and voltage adjustment functionality from the modulator and places it in a separate adaptive sample and hold circuit. This separation removes the complexity of handling range transitions from the modulator, allowing it to focus solely on modulation operations, thereby reducing design complexity while maintaining multi-range operation capability.
Solution Approach 2:
The adaptive sample and hold circuit acts as an intermediary between the loop filter output and the modulator. It detects the input signal range and adjusts the sample-and-hold voltage accordingly, seamlessly transitioning between voltage ranges without disturbing the modulator or the feedback loop, thus maintaining efficiency while enabling multi-range operation.
2Adaptability or versatility
If conventional circuits use the modulator to handle range transitions, then the amplifier can switch between supply voltages, but loop disturbances occur reducing efficiency
Solution Approach 1:
The range detector continuously monitors the input signal and determines the appropriate voltage range in advance. The adaptive sample and hold circuit pre-adjusts the sample-and-hold voltage to the appropriate level before the modulator needs to operate in a new range, enabling seamless transitions without loop disturbances and maintaining high efficiency throughout the voltage switching process.
3Device complexity
If the sample-and-hold-voltage is not adjusted for different input signal ranges, then the circuit operation is simple, but the sample-and-hold-voltage exceeds the predetermined voltage span reducing amplifier performance
Solution Approach 1:
The patent implements a dynamic adjustment mechanism where the sample-and-hold voltage automatically adapts to the input signal range. The range detector identifies the current signal range and the adaptive sample and hold circuit adjusts the held voltage accordingly, ensuring the voltage remains within the predetermined span. This dynamic adaptation maintains amplifier performance without requiring complex manual intervention.
Data Source
AI summary
An adaptive sample and hold circuit for signal amplifier range selection is presented. The adaptive sample and hold circuit has an input for receiving an input signal and an output for providing a sample-and-hold-voltage. It also includes a sample-and-hold-capacitor to generate the sample-and-hold-voltage from the input signal, and a range detector. The range detector is adapted to identify a range of the input signal and to adjust a voltage at the sample-and-hold-capacitor based on the range of the input signal to maintain the sample-and-hold-voltage within a predetermined voltage span.