Negative Voltage Generation Circuit Without LDO Regulator
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Solution Overview
Problem
Existing negative voltage generators for RF switches require large BGR circuits and LDO regulators, hindering miniaturization and failing to maintain a stable negative voltage within the desired range due to battery voltage fluctuations, leading to performance issues such as leakage current and harmonic degradation.
Innovation Solution
A negative voltage generation circuit that includes a clock generation circuit, a voltage control circuit to vary resistance based on power supply voltage, and a charge pump circuit to generate a stable negative voltage, eliminating the need for BGR and LDO regulators by stabilizing the voltage at the charge node and output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If BGR circuit and LDO regulator are used to maintain stable voltage, then voltage stability is improved, but chip area increases
Solution Approach 1:
The patent extracts and removes the BGR circuit and LDO regulator from the negative voltage generation system. Instead of using these separate stable voltage components, the invention integrates voltage stabilization functionality directly into the charge pump circuit through a control circuit that monitors and adjusts the charge pump's operation, thereby achieving voltage stability without the area overhead of traditional components.
Solution Approach 2:
The patent merges the voltage stabilization function with the charge pump circuit by introducing a control circuit that is directly coupled to the charge pump. This control circuit receives feedback about the output voltage and dynamically adjusts the charge pump's charging/discharging cycles to maintain stable voltage, combining what were previously separate functions (voltage generation and voltage stabilization) into a single integrated system.
2Device complexity
If battery voltage is used directly as charge pump input, then device complexity is reduced, but negative voltage stability deteriorates
Solution Approach 1:
The charge pump circuit performs self-regulation through the integrated control circuit that monitors the output voltage and automatically adjusts the charge pump's operation. The control circuit compares the actual output voltage with a reference voltage and modulates the charge pump's charging/discharging cycles accordingly, enabling the system to self-correct voltage variations caused by battery voltage fluctuations without external intervention.
Solution Approach 2:
The patent implements a feedback mechanism where the control circuit continuously monitors the charge pump's output voltage and uses this information to adjust the charge pump's operation. The control circuit receives feedback signals about voltage deviations and dynamically modifies the charging/discharging cycles to maintain the output voltage within the desired range, ensuring stability despite variations in battery voltage.
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 achieves a constant negative voltage generation without BGR and LDO regulators, maintaining voltage stability across battery voltage fluctuations, reducing chip size, and improving RF switch performance by minimizing leakage current and harmonic issues.
Implementation Method 1
a charge pump (CP) performing charging and discharging of a capacitor using a clock to generate a negative voltage
Data Source
AI summary
A negative voltage generation circuit includes a clock generation circuit configured to generate a first clock signal, a first voltage control circuit configured to vary a first resistance value based on a magnitude of a power supply voltage and further configured to control a magnitude of a voltage in a first charge node, based on the varied first resistance value, and a first charge pump circuit configured to charge a voltage, controlled by the first voltage control circuit, in a charge mode, based on the first clock signal, and further configured to output a first voltage, generated by the charging, as a first negative voltage.