SIMO Power Converter Ripple Reduction via Complementary Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional single inductor multiple output (SIMO) power converters face challenges with high ripple in output voltages due to lack of power supply during compensation cycles and are often expensive due to complex digital control schemes.
Innovation Solution
A SIMO power converter circuit with a control circuit comprising two control loops that manage the peak current and duty-cycle difference of switches M1 and M2, allowing for efficient power distribution across multiple outputs with reduced ripple through complementary operation of switches and diodes, using N-channel MOSFETs or other suitable switching devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional priority control scheme is used in SIMO converter, then output voltage compensation is achieved, but high ripple is generated in the cut-off output
Solution Approach 1:
The patent applies continuous conduction mode (CCM) operation where the inductor current continues to flow through both outputs simultaneously during specific time intervals. This is achieved by controlling switches M1 and M2 to operate in complementary pairs, ensuring that power delivery to both outputs VP and VN is continuous rather than intermittent. The inductor current waveform shown in FIG. 2A demonstrates this continuous flow, eliminating the high ripple that occurs when power delivery is cut off during compensation cycles in conventional priority control schemes.
Solution Approach 2:
The patent employs periodic switching of complementary switch pairs (M1-M2 and M3-M4) to alternately charge and discharge the inductor for different outputs. The switching controller generates periodic gate signals that cause the switches to operate in alternating intervals, creating a rhythmic pattern of power distribution. This periodic action, visible in the switching waveforms of FIG. 2A, enables controlled power steering to different outputs while maintaining continuous inductor current flow, thereby reducing voltage ripple compared to non-periodic priority control.
2Measurement precision
If digital control is used in SIMO power converter, then control precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent implements feedback control through voltage detection circuits that continuously monitor the output voltages VP and VN. The detected voltage signals are fed back to the switching controller, which uses this information to dynamically adjust the duty cycles of the complementary switch pairs. This closed-loop feedback mechanism, described in the control method sections, enables precise control of power distribution without requiring complex digital processing, achieving high control precision through simple analog feedback circuits.
Solution Approach 2:
The switching controller automatically adjusts the switching duty cycles based on the detected output voltage conditions without external intervention. The control circuit self-regulates by comparing the feedback voltage signals with reference values and autonomously generating the appropriate gate drive signals for the switches. This self-service capability, evident in the automatic duty cycle adjustment described in the control method, eliminates the need for complex digital control algorithms while maintaining high precision control.
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 reduces voltage ripple and enhances efficiency by dynamically controlling the duty-cycle of switches, providing a cost-effective control mechanism for SIMO power converters.
Implementation Method 1
an inductor L, two capacitors C1 and C2
Implementation Method 2
two capacitors C1 and C2
Data Source
AI summary
SIMO power converters and associated methods of control are disclosed herein. In one embodiment, a method of converting a signal input signal into multiple output signals includes supplying power to a plurality of output terminals based on a signal input signal, detecting a voltage at individual output terminals, determining an arithmetic relationship between the detected voltages of the output terminals, and adjusting the power supplied to the plurality of output terminals based at least in part on the determined arithmetic relationship between the detected voltages of the output terminals.