Charge Pump Pre-Charging for Lower Parasitic Capacitance Loss
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Solution Overview
Problem
Existing charge pump circuits face issues with high power loss and low efficiency due to excessive output voltage ripple and high light load power consumption, particularly in power transistors with large drain parasitic capacitance.
Innovation Solution
A pre-charge operation is introduced in the charge pump circuit, where the drain terminal of power transistors is charged to a pre-charge voltage before being charged to the main voltage, reducing power loss by minimizing direct charging across the parasitic capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If direct charging from third voltage to first voltage is used, then charging speed is fast, but power loss increases due to parasitic capacitance
Solution Approach 1:
The charging process is segmented into two distinct phases: a first charge period charging from third voltage to fourth voltage, and a second charge period charging from fourth voltage to first voltage. This segmentation allows optimization of each phase independently, reducing overall power loss while maintaining charging speed.
Solution Approach 2:
The pre-charging circuit performs preliminary action by charging the specified node to the fourth voltage before the main charging operation. This preliminary charging reduces the voltage differential during the main charging phase, thereby reducing power loss in power transistors with large drain parasitic capacitance.
2Use of energy by moving object
If pulse frequency modulation is used, then light load efficiency is high, but output voltage ripple increases
Solution Approach 1:
The patent changes operating parameters by introducing a pre-charge voltage level (fourth voltage) between the minimum (third voltage) and maximum (first voltage) operating voltages. This parameter change allows the circuit to operate more efficiently at light loads while reducing voltage ripple through controlled pre-charging before full voltage transitions.
3Object-generated harmful factors
If pulse amplitude modulation is used, then output voltage ripple is low, but light load power consumption increases
Solution Approach 1:
The patent implements dynamic operation by adaptively switching between different charging modes. The control circuit dynamically determines whether to use the pre-charge circuit based on operating conditions, allowing the system to maintain low voltage ripple while reducing power consumption at light loads through selective pre-charging operations.
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 pre-charge operation reduces power consumption by 10-30% across various frequencies and voltages, enhancing overall conversion efficiency and reducing power loss in power transistors.
Implementation Method 1
power loss of power transistors with large drain parasitic capacitance
Data Source
AI summary
A charge pump circuit including a voltage converter and a pre-charging circuit is provided. The voltage converter is configured to receive a first voltage, and convert the first voltage into a second voltage. The first voltage is larger than the second voltage. The pre-charging circuit is coupled to the voltage converter. The pre-charging circuit is configured to charge a specified node of the voltage converter from a third voltage to a fourth voltage in a first charge period. The voltage converter charges the specified node from the fourth voltage to the first voltage in a second charge period. The fourth voltage is larger than the third voltage, and the third voltage and the fourth voltage are between the first voltage and the second voltage.