Bootstrap Capacitor Charging During Low-Power Power Stage States
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Solution Overview
Problem
The transition from a low power state to a normal operation state in power stages is delayed due to the need to bias the power stage and charge the bootstrap capacitor, which disconnects paths and requires sufficient bootstrap voltage, leading to undesired delays.
Innovation Solution
A controller is configured to enable a low power state in a device with high and low side switching elements, allowing the low side switching element to charge the bootstrap capacitor during low power states, thereby reducing the transition time by maintaining some components active and charging the capacitor without consuming additional power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the power stage is put into low power state to preserve energy, then power consumption is reduced, but the transition time to normal operation state increases due to bootstrap capacitor charging delay
Solution Approach 1:
The bootstrap capacitor is charged during the low power state before the transition to normal operation is needed. The low side switching element is operated to charge the bootstrap capacitor in advance, so that when the power stage needs to transition to normal operation, the capacitor is already charged and ready, eliminating the charging delay during transition.
2Loss of energy
If connection paths are disconnected during low power state to minimize current flow, then energy preservation is improved, but the power stage requires re-biasing and capacitor charging to resume operation
Solution Approach 1:
The power stage uses its own low side switching element to charge the bootstrap capacitor during the low power state, without requiring external intervention or complex re-biasing circuits. The system serves itself by maintaining the ability to charge the capacitor even when in low power mode, simplifying the transition back to normal 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
This approach reduces the delay in transitioning from a low power state to a normal operation state by allowing the bootstrap capacitor to be charged during low power states, such as nap mode, while preserving energy and power, thus enhancing the efficiency and speed of the power stage operations.
Implementation Method 1
operate the low side switching element of the device to charge a bootstrap capacitor of the device
Data Source
AI summary
Systems, apparatuses, and methods for charging a bootstrap capacitor of a device during low power states are described. In an example, an apparatus can include a controller configured to enable a low power state of the device. The device can include a high side switching element and a low side switching element. The controller can, in response to the low power state of the device being enabled, operate the low side switching element of the device to charge the bootstrap capacitor of the device. The controller can, in response to the low power state of the device being enabled and a level of a control signal being a first level, activate the low side switching element to charge the bootstrap capacitor of the device.