Capacitive Buck-Boost Converter for Multi-Voltage Bias
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Solution Overview
Problem
Electronic circuits face challenges in providing optimal bias voltages due to noise and variability in battery-supplied DC voltage, requiring efficient power management to accommodate varying voltage requirements across different circuit components, such as transistors and MOSFETs, while minimizing performance degradation and leakage.
Innovation Solution
A multiple output capacitive buck/boost converter system on a chip that charges input capacitors and switches them to output capacitors via a controlled switch array, using a state machine to generate multiple voltages efficiently, with variable resistance to manage current peaks and reduce noise, allowing for both higher and lower output voltages than the input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a higher bias voltage is used to drive transistors in amplifier applications, then the amplifier avoids saturation and operates properly, but transistor leakage increases and performance degrades due to gate oxide breakdown
Solution Approach 1:
The power management system segments the voltage supply by providing different bias voltages to different circuit blocks. The voltage regulator generates multiple output voltages (first output voltage and second output voltage) that are selectively supplied to RF circuitry, baseband circuitry, and other blocks based on their specific requirements, allowing each block to operate at its optimal voltage level
Solution Approach 2:
Different circuit blocks are assigned different voltage levels according to their local requirements. The RF circuitry receives a first bias voltage optimized for amplifier operation, while other blocks receive a second bias voltage optimized for their specific functions, ensuring each block operates with the appropriate voltage quality for its task
2Loss of energy
If a lower bias voltage is used to reduce transistor leakage, then power consumption decreases, but amplifier circuits may saturate and fail to operate properly
Solution Approach 1:
The power management system segments the voltage supply by providing different bias voltages to different circuit blocks. The voltage regulator generates multiple output voltages (first output voltage and second output voltage) that are selectively supplied to RF circuitry, baseband circuitry, and other blocks based on their specific requirements, allowing each block to operate at its optimal voltage level
Solution Approach 2:
Different circuit blocks are assigned different voltage levels according to their local requirements. The RF circuitry receives a first bias voltage optimized for amplifier operation, while other blocks receive a second bias voltage optimized for their specific functions, ensuring each block operates with the appropriate voltage quality for its task
3Reliability
If multiple bias voltages are supplied to different circuit blocks, then each block operates optimally, but the power management system complexity increases
Solution Approach 1:
The voltage regulator is designed as a universal power management device that can generate multiple output voltages and supply them to different circuit blocks. The single regulator handles both the first output voltage for RF circuitry and the second output voltage for other blocks, eliminating the need for multiple separate regulators and reducing overall system complexity
Solution Approach 2:
The power management system dynamically adjusts voltage supply based on operational mode. The regulator can switch between generating the first output voltage for high-performance RF operation and the second output voltage for low-power operation, and can also adjust the second output voltage based on the operational state of other circuit blocks, optimizing performance while managing complexity
4Power
If the voltage regulator supplies power during high-performance operation, then RF circuitry operates at full capability, but power consumption increases
Solution Approach 1:
The power management system dynamically adjusts voltage supply based on operational mode. The regulator can switch between generating the first output voltage for high-performance RF operation and the second output voltage for low-power operation, and can also adjust the second output voltage based on the operational state of other circuit blocks, optimizing performance while managing complexity
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 system effectively manages power across different circuit blocks, reducing noise and maintaining high efficiency (>90%) by dynamically adjusting switching sequences and capacitance values, ensuring optimal voltage regulation and minimizing power losses.
Implementation Method 1
there may be noise in the bias voltage, which may be mitigated by capacitive filters
Implementation Method 2
charging one or more input capacitors via an input voltage. One or more output voltages may be generated on a chip by switching one or more of the charged input capacitors to one or more output capacitors
Data Source
AI summary
Methods and systems for a multiple output capacitive buck/boost converter are disclosed and may include charging one or more input capacitors via an input voltage. One or more output voltages may be generated on a chip by switching the charged input capacitors to output capacitors via a switch array on the chip. The switch array may be controlled via a state machine. A constant current and/or voltage may be generated for the one or more output voltages via one or more current and/or voltage comparators. A variable resistance may be coupled in series with one or more switches in the switch array. The one or more input capacitors may be discrete capacitors external to the chip and/or integrated within the chip. One or more of the output voltages may be greater than the input voltage, or may be less than the input voltage.