Amplifier Supply Tracking for Wide Common-Mode Input Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Amplifiers face limitations in performance due to the limited common-mode input voltage operating range and linearity issues, particularly when using high voltage transistors, which can lead to breakdown voltages being exceeded by low voltage transistors in input amplification stages.
Innovation Solution
A power supply control block is implemented to generate power high and power low supplies for the input amplification stage, adjusting voltage levels based on a reference signal indicative of the common-mode input voltage, allowing the use of low voltage transistors without exceeding their breakdown voltages by maintaining a constant voltage difference between the power supplies and tracking the common-mode input voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high voltage transistors are used in the input amplification stage to expand the common-mode input voltage operating range, then the operating range is improved, but linearity deteriorates and breakdown voltages are exceeded
Solution Approach 1:
The patent dynamically changes the power supply voltage parameters for the input amplification stage based on the common-mode input voltage level. When the common-mode voltage exceeds a threshold, the power supply control block adjusts the voltage levels to maintain proper transistor operation, preventing breakdown while preserving linearity. This resolves the contradiction by adapting voltage parameters rather than being constrained by fixed high or low voltage operation.
2Reliability
If low voltage transistors are used in the input amplification stage to improve linearity, then linearity is improved, but the common-mode input voltage operating range is limited
Solution Approach 1:
The patent implements a dynamic power supply control system that continuously monitors the common-mode input voltage and adjusts the power supply voltages accordingly. This dynamic adjustment allows low voltage transistors to operate effectively across a wide common-mode voltage range by adapting the voltage levels in real-time, resolving the contradiction between maintaining linearity and expanding operating range.
3Device complexity
If fixed power supply voltages are used for the input amplification stage, then device complexity is reduced, but performance deteriorates under varying common-mode input voltages
Solution Approach 1:
The patent employs a feedback mechanism where the power supply control block receives the common-mode input voltage signal and uses it to adjust the power supply voltages for the input amplification stage. This feedback loop ensures that the power supply voltages are optimized for the current operating conditions, maintaining high performance without requiring overly complex external control circuitry.
Data Source
AI summary
Apparatus and methods for amplifier power supply control are provided. In certain implementations, an amplifier includes an input amplification stage and a power supply control block for generating a power high supply and a power low supply for the input amplification stage. The power supply control block receives a reference signal indicative of a common-mode input voltage of the amplifier, and the power supply control block adjusts a voltage level of the power high and power low supplies while maintaining a substantially constant voltage difference between the power high and power low supplies. The power supply control block changes the voltage level of the power high and power low supplies based on the reference signal such that the voltage levels of the power high and power low supplies move in relation to the common-mode input voltage.