Switched-Capacitor Buck Power Path for Low-Voltage Silicon Batteries
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Solution Overview
Problem
Lithium batteries with silicon anode materials have a larger capacity and remaining electricity at low voltages, but current low-voltage charging and discharging technologies are not mature, preventing these batteries from directly supplying power to systems.
Innovation Solution
A chip design that includes a first switch transistor, a comparator, a voltage sampling circuit, a control circuit, a switched capacitor circuit, and a buck circuit, which collectively control the battery to boost its discharge voltage and supply power to the system when the input source's loading capability is insufficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a silicon anode battery is used to increase capacity and remaining electricity at low voltage, then the battery capacity is improved, but the low-voltage charging and discharging technology is not mature preventing direct power supply to the system
Solution Approach 1:
The patent introduces a voltage boosting circuit as an intermediary device between the silicon anode battery and the system. This mediator converts the low battery voltage (e.g., 2.5V) to the required system operating voltage (e.g., 5V), enabling the battery to power the system even when its voltage is insufficient. This resolves the technology maturity issue by providing a practical voltage conversion solution.
Solution Approach 2:
The patent changes the voltage parameter of the battery output through the voltage boosting circuit. By transforming the battery's low voltage state (2.5V-3.0V) into a usable high voltage state (5V), the system can utilize silicon anode batteries with higher capacity that would otherwise be incompatible with standard system voltage requirements.
2Reliability
If additional power supply paths are added to enable low-voltage battery to supply power, then the power supply capability is improved, but the chip space and hardware costs increase
Solution Approach 1:
The voltage boosting circuit is designed to serve multiple functions: it can operate in battery power supply mode (boosting battery voltage to system voltage), in charging mode (converting input voltage for battery charging), and in power path selection (managing the transition between different power sources). This multi-functionality eliminates the need for separate dedicated circuits for each function, reducing overall chip space requirements.
Solution Approach 2:
The patent merges the voltage boosting function with the existing power management circuitry. The same circuit infrastructure is used for both voltage boosting during battery discharge and voltage conversion during charging operations, consolidating multiple power management functions into a unified circuit design that minimizes hardware overhead and chip area.
3Power
If the input source loading capability is insufficient, then the system voltage drops, but the battery cannot directly supply power due to low voltage
Solution Approach 1:
The voltage boosting circuit acts as a mediator that decouples the battery's low voltage output from the system's voltage requirements. When the input source cannot maintain adequate voltage under load, the boosting circuit actively converts the battery's low voltage (2.5V-3.0V) to the required system voltage (5V), ensuring continuous stable power supply without voltage drop issues.
Solution Approach 2:
The voltage boosting circuit performs preliminary voltage conversion before power is supplied to the system. By pre-boosting the battery voltage to the required level, the system receives stable voltage regardless of the battery's actual voltage state or input source capabilities, preventing voltage drop before it affects system operation.
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 allows lithium batteries with silicon anode materials to continuously supply power to systems at low voltages without the need for additional power supply paths, reducing chip space and hardware costs while preventing battery electricity waste.
Implementation Method 1
control the switched capacitor circuit to boost a discharge voltage of the battery to a first voltage
Implementation Method 2
control the buck circuit to convert the first voltage into a target voltage
Data Source
Figure 1~2a
Figure 2b
Figure 2c~3a
AI summary
Embodiments of this application provide a chip, a terminal device, and a system power supply method. The chip includes a first switch transistor, a first comparator, a voltage sampling circuit, a control circuit, a switched capacitor circuit, and a buck circuit. The first switch transistor is connected to an input source and the switched capacitor circuit, the switched capacitor circuit is connected to a battery, and the buck circuit is connected to the first switch transistor and a system. The voltage sampling circuit is connected to the system, and the first comparator is connected to the voltage sampling circuit, a reference voltage, and the control circuit. The first comparator is configured to output a level of the first comparator in response to a result of comparison between a collected voltage of the system and the reference voltage. The control circuit is configured to: in response to the level of the first comparator, switch off the first switch transistor, control the switched capacitor circuit to boost a discharge voltage of the battery, and control the buck circuit to further convert the discharge voltage into a target voltage, so that the battery at a low voltage supplies power to the system Because in the technical solution of this application, an additional battery power supply path is not required, chip space and hardware costs can be reduced.