DC/DC Converter Controller with Delay Units for Switch Misalignment
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Solution Overview
Problem
Conventional DC/DC converters suffer from inefficiencies due to fixed-frequency switching, leading to unnecessary power consumption and switching losses, especially when powering light loads, and can experience switch misalignment causing damage and inefficiency.
Innovation Solution
A controller for DC/DC converters that generates PWM signals to control multiple switches, allowing for alternation between power receive and conserve modes, and includes delay units to prevent switch misalignment and optimize power conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed-frequency switching is used to drive switches, then the switching circuit operates reliably, but switching losses increase and power conversion efficiency decreases under light load conditions
Solution Approach 1:
The patent implements dynamic frequency adjustment by using a pulse generator that produces drive signals with variable pulse widths based on load conditions. Under light load conditions, the pulse width is reduced or switching is inhibited entirely, dynamically adapting the switching frequency to minimize losses while maintaining reliable operation when needed.
Solution Approach 2:
The patent changes the temporal parameter of the drive signal (pulse width and frequency) based on operating conditions. The pulse generator adjusts the duration and timing of drive signals to switches, transforming the fixed-frequency operation into variable-frequency operation that optimizes efficiency across different load conditions.
2Loss of energy
If pulse width is reduced under light load conditions, then switching losses are reduced, but turn-on and turn-off delays become significant relative to the ON time
Solution Approach 1:
The patent applies preliminary timing adjustments by incorporating delay circuits that pre-compensate for switch turn-on and turn-off delays. The pulse generator is designed to account for these inherent delays, ensuring that the effective ON time remains sufficient for proper switch operation even when the overall pulse width is reduced for light load conditions.
3Device complexity
If drivers have different time delays, then circuit simplicity is maintained, but switch misalignment occurs causing simultaneous conduction and potential damage
Solution Approach 1:
The patent introduces delay circuits as intermediary elements between the pulse generator and the switch drivers. These delay circuits act as mediators that synchronize the drive signals to compensate for differences in driver response times, preventing simultaneous conduction of complementary switches while maintaining overall circuit simplicity.
Solution Approach 2:
The patent applies preliminary anti-action by using delay circuits to pre-adjust the timing of drive signals in opposition to the natural timing differences caused by driver non-ideality. This preemptive timing correction prevents the harmful effect of simultaneous switch conduction before it can occur.
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 switching losses, improves power conversion efficiency, and prevents switch damage by dynamically adjusting switching frequencies and modes based on load conditions, enhancing overall performance and reliability.
Implementation Method 1
The transformer T receives the input power via the switches SW1 and SW2, and converts the input power to output power. Moreover, a primary current is generated through the primary winding of the transformer T, and magnetically, a secondary current is generated through the secondary winding of the transformer T.
Data Source
AI summary
A controller for a DC/DC converter controls a first, second, third, and fourth switches according to pulse signals generated alternately. The controller turns off the third switch on detection of a first edge of a first pulse signal, turns on the first switch after a delay from the detection of the first edge, turns off the fourth switch on detection of a second edge of the first pulse signal, turns on the second switch after a delay from the detection of the second edge, turns off the first switch on detection of a third edge of a second pulse signal, turns on the third switch after a delay from the detection of the third edge, turns off the second switch on detection of a fourth edge of the second pulse signal, and turns on the fourth switch after a delay from the detection of the fourth edge.