Power Supply Selection Switch Circuit for Compact PA Modules
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Solution Overview
Problem
The existing communication terminal systems require multiple power management integrated circuits (PMICs) to support various communication methods, leading to increased manufacturing costs due to the large number of power components needed.
Innovation Solution
A power selection switch circuit that selects either one or both of two power supply voltages and supplies them to a power amplifier, using n-type transistors to reduce the number of PMICs required and minimize the size of the power amplifier module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pair of n-type and p-type transistors is used as a switch core to reduce on-resistance for high DC input voltage, then the on-resistance is reduced, but the area occupied by the p-type transistor increases, leading to increased power amplifier module size and price
Solution Approach 1:
The patent uses two n-type transistors instead of a conventional n-type and p-type transistor pair. By using the same type of transistor (n-type) for both switching elements, the design achieves homogeneity in transistor type, which eliminates the need for large-sized p-type transistors while maintaining low on-resistance performance through parallel configuration and charge pumping voltage enhancement.
2Adaptability or versatility
If multiple power management integrated circuits (PMICs) are used to support various communication methods, then communication compatibility is improved, but the number of power components increases, leading to increased manufacturing cost
Solution Approach 1:
The power selection switch circuit enables a single PMIC to serve multiple power amplifiers by providing selective power supply to different amplifiers based on communication method requirements. This multi-functional approach allows one PMIC to replace what would traditionally require multiple PMICs, reducing the total number of power components while maintaining support for various communication methods.
3Area of stationary object
If n-type transistors are used instead of p-type transistors to reduce the area of the power amplifier module, then the module size is reduced, but additional control circuitry is needed to manage the switching of n-type transistors with higher voltage requirements
Solution Approach 1:
The patent introduces a charge pumping circuit as an intermediary mechanism to generate the high voltage required for controlling n-type transistor switching. This charge pumping circuit acts as a mediator that converts the available lower voltage to the necessary higher voltage level, enabling n-type transistor operation without directly complicating the main switching control architecture.
Solution Approach 2:
The control circuit generates the charge pumping voltage in advance before the n-type transistors need to switch. By preparing the high voltage condition beforehand through charge pumping, the actual switching operation can proceed efficiently without adding complexity to the real-time control logic, as the voltage preparation is done in a preliminary stage.
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 reduces the number of power components and manufacturing costs while preventing simultaneous turn-on of transistors to protect the power amplifier from overcurrent.
Implementation Method 1
a first switching control signal having a first voltage generated by charge pumping the first power supply voltage, and supply the first power supply voltage to a power supply terminal of the power amplifier when turned on; and an n-type second transistor configured to turn on in response to a second switching control signal having a second voltage generated by charge pumping the second power supply voltage
Data Source
AI summary
A power selection switch circuit configured to select either one or both of a first power supply voltage and a second power supply voltage, and supply the selected power supply voltage to a power amplifier, the power selection switch circuit includes: an n-type first transistor configured to turn on in response to a first switching control signal having a first voltage generated by charge pumping the first power supply voltage, and supply the first power supply voltage to a power supply terminal of the power amplifier when turned on; and an n-type second transistor configured to turn on in response to a second switching control signal having a second voltage generated by charge pumping the second power supply voltage, and supply the second power supply voltage to the power supply terminal of the power amplifier when turned on.