Digital Active Diode Circuit With Dual-Threshold Switching
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Solution Overview
Problem
Existing active diode circuits face challenges in achieving fast response times with low quiescent power consumption, particularly when driving large pass transistors, and often suffer from instability due to the use of amplifiers or comparators.
Innovation Solution
A digital active diode circuit employing a switching mechanism with two comparators and an array of binary-weighted switches, where the comparators update the switching state based on threshold voltage differences, allowing for fast response without high quiescent power consumption and minimizing unnecessary switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an amplifier is used to drive a large pass transistor to achieve low-Ohmic forward conduction, then the forward conduction resistance is reduced, but the power consumption increases significantly
Solution Approach 1:
The patent divides the pass transistor into multiple parallel transistors (first pass transistor and second pass transistor) that are selectively controlled by two separate comparators. This segmentation allows the circuit to use only the necessary transistor capacity for each operating condition, reducing unnecessary power consumption while maintaining low forward conduction resistance when needed.
Solution Approach 2:
The patent changes the operational parameters by using two comparators with different threshold voltages (first threshold voltage and second threshold voltage) to control different transistor configurations. This allows dynamic adjustment of the conduction path based on the input-output voltage difference, optimizing power consumption across different operating conditions.
2Use of energy by moving object
If a comparator is used instead of an amplifier to reduce power consumption, then power consumption is reduced, but instability occurs due to oscillating switch resistance
Solution Approach 1:
The patent uses two separate comparators (first comparator and second comparator) with different threshold voltages to control different transistor states. This segmentation prevents the single comparator oscillation problem by providing hysteresis-like behavior through the threshold difference, stabilizing the circuit while maintaining low power consumption.
Solution Approach 2:
The patent anticipates potential instability by designing the switching behavior to occur only when the voltage difference exceeds specific thresholds. This beforehand cushioning prevents oscillations by ensuring that switching decisions are made only when clearly warranted by the voltage conditions, avoiding the instability that occurs with marginal switching points.
3Speed
If a large pass transistor is used to achieve fast response time, then the response speed is improved, but the quiescent power consumption increases
Solution Approach 1:
The patent segments the pass transistor functionality into multiple smaller transistors that are activated only when needed. The comparators monitor the voltage difference and selectively turn on the appropriate transistors, providing fast response when voltage changes occur while keeping quiescent power consumption low when the circuit is in steady state.
Solution Approach 2:
The patent implements periodic monitoring and switching control through the comparators that continuously check the voltage difference between input and output. This periodic action allows the circuit to respond quickly to changes while remaining in a low-power state during stable operating conditions.
Data Source
AI summary
A digital active diode circuit for letting current pass in one direction and substantially blocking current in the opposite direction is presented. The circuit contains switching means comprising an array of switches, a first comparison unit coupled to the digital active diode circuit input and output. The first comparison unit updates its output if the difference between their inputs is higher than a first threshold voltage, and a second comparison unit being coupled to the digital active diode circuit output and input. The second comparison unit updates its output if the difference between its inputs is lower than a second threshold voltage. The switching means switches on or off at least one switch based on the comparisons performed by the first comparison unit and the second comparison unit and wherein the first threshold voltage is different from the second threshold voltage.