Current Detection Circuit Eliminates External Resistors
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Solution Overview
Problem
Current current detection methods in chargers require external detection resistors, leading to increased power consumption and costs due to additional pins and components.
Innovation Solution
A current detection circuit comprising a current sampling branch, switch branch, current mirror branch, capacitor branch, and feedback branch, which uses a control branch to manage duty cycles and represent currents without external resistors, allowing for efficient detection of currents flowing into an electrical load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an external detection resistor is used to detect current, then current detection can be achieved, but power consumption increases and additional pins are required
Solution Approach 1:
The patent merges the current detection function with the existing charge pump circuit by using the same capacitor and switching elements. The detection resistor is integrated into the feedback path of the charge pump, allowing current detection without requiring external components. This combining of functions eliminates the need for separate detection resistors and reduces power consumption.
Solution Approach 2:
The capacitor in the charge pump circuit serves dual purposes: it acts as both the charge storage element for voltage conversion and as the detection element for current measurement. By making the detection function universal to the existing circuit elements, the patent eliminates the need for dedicated detection components, thereby reducing power consumption and component count.
2Measurement precision
If an external detection resistor is used to detect current, then current detection can be achieved, but additional pins and components are required increasing cost
Solution Approach 1:
The patent merges the current detection function with the existing charge pump circuit by using the same capacitor and switching elements. The detection resistor is integrated into the feedback path of the charge pump, allowing current detection without requiring external components. This combining of functions eliminates the need for separate detection resistors and reduces power consumption.
Solution Approach 2:
The patent extracts the current detection capability from the external component domain and relocates it entirely within the integrated circuit. By taking out the detection function from external resistors and implementing it using internal capacitors and switching elements, the patent eliminates the need for external detection resistors and associated pins, thereby reducing device complexity and cost.
3Use of energy by moving object
If duty cycle modulation is used for current detection, then power consumption is reduced, but control complexity increases
Solution Approach 1:
The patent employs feedback mechanisms where the charge pump output voltage, which is modulated by duty cycle variations, is fed back to the control logic. This feedback allows the system to automatically adjust the duty cycle based on the detected current, reducing power consumption without requiring complex external control circuits. The feedback loop inherently manages the control complexity within the integrated circuit.
Solution Approach 2:
The control circuit serves itself by using the duty cycle modulation directly as the detection signal. The charge pump's natural response to load current variations, expressed through duty cycle changes, is directly utilized for detection purposes. This self-service approach eliminates the need for separate detection circuits and reduces overall system complexity while maintaining low power consumption.
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 solution reduces power consumption and costs by eliminating the need for external detection resistors and additional pins, enabling precise current detection and control without increasing the complexity of the charger design.
Implementation Method 1
a capacitor branch (40), configured to charge in response to the first charging current and discharge in response to the first discharging current
Data Source
AI summary
A current detection circuit includes a current sampling branch, a switch branch, a first current mirror branch, a capacitor branch, a feedback branch and a control branch. The control branch receives the second current and outputs the first current and the first voltage signal. The current sampling branch outputs a first discharging current. The switch branch establishes and disconnects the connection between the first current mirror branch and the capacitor branch. The capacitor branch is charged in response to the first charging current and discharged in response to the first discharging current. The first current mirror branch outputs the first charging current. The feedback branch adjusts the second charging current to adjust the first charging current, so that the total charge of the capacitor branch is balanced with the total charge of discharge within one switching cycle, so that the first current is represented by the first charging current.