Adaptive Miller Compensation Voltage Regulator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage regulators experience transient voltage ripple when adapting to light or heavy loads due to their inability to dynamically adjust closed-loop phase margin with fixed resistor-capacitor compensation circuits.
Innovation Solution
A voltage regulator with adaptive Miller compensation, featuring a first amplifier, second amplifier, adaptive compensation circuit, bias circuit, and output circuit, where the compensation transistor's resistance varies with load conditions controlled by a bias control voltage generated from a mirror current, allowing operation in deep triode regions with either weakly- or strongly-inverted channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional compensation circuit with fixed resistor and capacitor is used, then the circuit structure is simple, but the closed-loop phase margin cannot be dynamically adjusted causing transient voltage ripple under light or heavy load conditions
Solution Approach 1:
The patent applies dynamics by making the compensation circuit adaptive to load conditions. The compensation transistor's resistance dynamically changes based on load current detected by the bias circuit, allowing the phase margin to be automatically adjusted for light or heavy loads, resolving the contradiction between adaptability and complexity
Solution Approach 2:
The patent changes the resistance parameter of the compensation transistor dynamically. The bias circuit generates a bias control voltage that adjusts the compensation transistor's resistance based on load conditions, enabling the phase margin to adapt without requiring multiple fixed compensation circuits, thus maintaining simplicity while achieving adaptability
2Reliability
If the compensation transistor operates in deep triode region with dynamic resistance control, then voltage ripple is reduced and phase margin is maintained, but the control circuit complexity increases
Solution Approach 1:
The bias circuit automatically generates the appropriate bias control voltage based on the load current without external intervention. The circuit self-regulates by detecting its own operating conditions and adjusting the compensation transistor resistance accordingly, improving reliability while minimizing the need for complex external control circuits
Solution Approach 2:
The bias circuit implements feedback by monitoring the load current and using it to control the bias control voltage that adjusts the compensation transistor's resistance. This feedback mechanism ensures the phase margin is maintained under varying load conditions, enhancing voltage regulation stability without requiring overly complex control logic
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
This design ensures a sufficient phase margin of 45° or above in both light and heavy loads, significantly reducing voltage ripple effects by dynamically adjusting the compensation circuit's resistance in response to load changes.
Implementation Method 1
The resistance of the compensation transistor varies according to a load of the voltage regulator under control of the bias control voltage
Implementation Method 2
The bias circuit generates a mirror current that copies at least a portion of a current flowing in the output circuit
Implementation Method 3
The adaptive compensation circuit includes a compensation capacitor and a compensation transistor that are serially connected
Data Source
AI summary
A voltage regulator with adaptive Miller compensation includes a first amplifier and a second amplifier. An adaptive compensation circuit includes serially connected compensation capacitor and a compensation transistor coupled to the second amplifier. A bias circuit generates a proper bias control voltage to dynamically control the adaptive compensation circuit in a manner that the adaptive compensation transistor operates in a deep triode region with weakly-inverted channel or strongly-inverted channel. An output circuit generates an output voltage according to which the feedback voltage is generated. The resistance of the compensation transistor varies according to a load of the voltage regulator under control of the bias control voltage. The bias circuit generates a mirror current that copies at least a portion of a current flowing in the output circuit, and the bias control voltage is then generated according to the mirror current.