Charge Pump Driver Circuit for Boost-Mode Output Current Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery charger systems face challenges in effectively limiting output current when operating in boost mode, leading to quick battery drainage due to inadequate protection against reverse current and negative voltage transients.
Innovation Solution
The proposed solution involves a battery charging system that includes a transistor coupled between an input voltage terminal and an output voltage terminal, with a driver circuit and a charge pump to regulate the output current. This system uses a current sink and a charge pump to manage the current flow, providing protection against reverse current and negative voltage transients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a current limit circuit sets the duty cycle to zero until dropout condition, then the output current is limited, but the battery drains quickly due to difficulty in maintaining current limitation
Solution Approach 1:
The patent introduces a charge pump circuit as an intermediary component between the main switching transistor and the current limit circuit. This charge pump maintains a stable voltage reference that enables the current limit circuit to continuously regulate output current even during dropout conditions, preventing the rapid battery drainage that occurs when duty cycle is simply set to zero. The charge pump acts as a mediator that bridges the gap between the control circuit and the power delivery path, ensuring smooth current limitation without abrupt interruptions.
2Adaptability or versatility
If the voltage converter operates in boost mode without adequate protection, then power can be supplied to external devices, but reverse current and negative voltage transients cause harmful effects
Solution Approach 1:
The patent applies preliminary anti-action by incorporating protection circuits that preemptively counteract reverse current and negative voltage transients before they can cause damage. The circuit includes clamping diodes and transient voltage suppression elements positioned to immediately counteract harmful voltage spikes and reverse current flows as soon as they occur during boost mode operation. This preliminary protective action allows the system to safely operate in both charging and power delivery modes without suffering from the harmful effects of electrical transients.
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 effectively regulates the output current in boost mode, preventing quick battery drainage and ensuring safe operation by protecting against reverse current and negative voltage transients.
Implementation Method 1
A charge pump has a charge pump input and a charge pump output. The charge pump input is coupled to the input voltage terminal.
Implementation Method 2
A current sink is coupled between the charge pump output and a ground terminal, and has a current sink control terminal.
Data Source
AI summary
Described embodiments include a charger circuit with a charge pump having a charge pump input and a charge pump output. The charge pump input is coupled to an input voltage terminal. A current sink is coupled between the charge pump output and a ground terminal, and has a current sink control terminal. A transistor is coupled between the input voltage terminal and an output voltage terminal, and has a control terminal. A driver circuit has a driver input, a driver output, a positive rail input, and a negative rail input. The driver output is coupled to the control terminal. The positive rail input is coupled to the charge pump output. The negative rail input is coupled to the output voltage terminal.