Dual-Output Charge Pump Circuit for RF Switch Leakage Reduction
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Solution Overview
Problem
RF switch circuits face challenges in achieving optimal voltage levels for driving RF switches, as the power voltage supplied from external sources often differs from the required voltage levels for maximum performance, particularly in silicon on insulator (SOI) and field effect transistor (FET) processes.
Innovation Solution
A charge pump circuit is designed with specific configurations of switches, capacitors, and resistors to generate two output voltages from a single input power voltage, where the first output voltage is twice the input voltage and the second output voltage is less than the first, applied to the body and gate terminals of an RF switch respectively, utilizing a variable resistor to adjust the second output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a typical voltage regulator is used to generate the required voltage levels, then the circuit complexity increases and additional components are required, but the charge pump circuit achieves voltage generation without a typical voltage regulator by using a simplified switch-capacitor network
Solution Approach 1:
The patent replaces the traditional voltage regulator (electronic control system) with a charge pump circuit based on switches and capacitors (electromechanical system). The voltage regulation function is achieved through periodic charging and discharging of capacitors controlled by switches, eliminating the need for complex voltage regulator components while maintaining reliable voltage generation.
Solution Approach 2:
The patent divides the voltage generation function into multiple independent capacitor stages (first capacitor, second capacitor, third capacitor) that can be independently controlled by switches. Each capacitor contributes to the overall voltage multiplication, allowing the system to achieve the required voltage levels through a simplified segmented approach rather than a single complex regulator.
2Object-generated harmful factors
If the same voltage is applied to both gate and body terminals, then the circuit design is simpler, but applying distinct voltages to gate and body terminals reduces leakage currents and enhances RF switch performance
Solution Approach 1:
The patent applies different voltage levels to different terminals of the RF switch: the first output voltage (higher level) is applied to the body terminal while the second output voltage (lower level) is applied to the gate terminal. This local differentiation of voltage quality optimizes the performance of each terminal specifically - the higher body voltage reduces leakage while the lower gate voltage maintains proper switching control.
Solution Approach 2:
The patent extends the voltage generation from a single-output system to a two-output system by adding another capacitor stage and switch. This dimensional expansion allows simultaneous provision of two different voltage levels from the same input, enabling distinct gate and body terminal voltages without requiring separate voltage generation systems.
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 configuration allows for efficient voltage generation without a typical voltage regulator, effectively driving RF switches and reducing leakage currents by applying distinct voltages to the gate and body terminals, thereby enhancing RF switch performance.
Implementation Method 1
a first capacitor configured to have a first end connected to a second end of the first switch; a second capacitor connected between a second end of the first capacitor and a second end of the second switch
Data Source
AI summary
A charge pump circuit is provided. The charge pump circuit includes a first switch configured to have a first end connected to an input terminal that receives a power voltage; a second switch configured to have a first end connected to the input terminal; a first capacitor configured to have a first end connected to a second end of the first switch; a second capacitor connected between a second end of the first capacitor and a second end of the second switch; a third switch connected between the second end of the second switch and ground; a fourth switch connected between the first end of the first capacitor and a first output terminal and configured to output a first output voltage; and a fifth switch connected between a second output terminal and a node between the first capacitor and the second capacitor, and configured to output a second output voltage.