Self-Tracking Pre-Driver Control for Dual Mode Power Supplies

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Solution Overview

Problem

Current switched-mode power supply designs require complex and space-consuming pre-driver control circuitry for both boost and buck-boost modes, necessitating multiple independent pre-drivers that increase the size of integrated circuits and risk damage to output transistors.

Innovation Solution

Implementing a self-tracking pre-driver control system that uses a single pre-driver control per pre-driver, with a bootstrap circuit charging capacitors during charge phases and selecting the appropriate voltage for the pre-driver based on the topology, ensuring the high-side pre-driver supply voltage remains within a safe range for both boost and buck-boost operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple independent pre-driver circuits are used for boost and buck-boost modes, then the power supply can operate in both modes, but the die area and circuit complexity increase significantly

Engineering Contradiction:

Improvedual mode operation capabilityVSAvoidpre-driver control circuitry complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the functionality of multiple independent pre-driver circuits into a single shared pre-driver control unit. The controller 140 receives mode selection signals and dynamically configures the single pre-driver 130 to operate in either boost or buck-boost mode, eliminating the need for separate dedicated pre-driver circuits for each mode while maintaining full operational capability in both modes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single pre-driver control circuit 130 is designed with universal functionality to handle both boost and buck-boost operating modes. The controller 140 adjusts the pre-driver configuration based on the operating mode, allowing the same hardware component to perform multiple functions that previously required separate dedicated circuits, thereby reducing overall circuit complexity and die area.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple independent pre-driver circuits are used, then both operating modes are supported, but the die area increases

Engineering Contradiction:

Improvesupport for boost and buck-boost modesVSAvoiddie area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple pre-driver control circuits into a single shared control unit that serves both boost and buck-boost modes. By consolidating the control logic and circuitry into one unified structure rather than maintaining separate independent circuits, the die area required for pre-driver control is significantly reduced while preserving full support for both operating modes.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If multiple independent pre-drivers are used, then mode flexibility is achieved, but the risk of transistor damage increases due to potential conflicts

Engineering Contradiction:

Improvemode switching flexibilityVSAvoidtransistor protection

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The controller 140 implements feedback-based control by monitoring the operating mode and dynamically adjusting the pre-driver configuration accordingly. When switching between boost and buck-boost modes, the controller receives mode selection signals and automatically configures the pre-driver to the appropriate state, preventing conflicting conditions that could damage the transistors while maintaining flexible mode switching capability.

Inventive Principle:

Principle #23Feedback

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 complexity and size of the circuitry while preventing damage to transistors by maintaining the high-side pre-driver supply voltage within a desired range, supporting both boost and buck-boost topologies with a single pre-driver control, thus optimizing die space and performance.

Implementation Method 1

a first capacitor is charged at a first bootstrap circuit and a second capacitor is charged at a second bootstrap circuit during the charge phase

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS7719245B2Methods and apparatus to provide self-tracking pre-driver controls

Publication Date: 2010.05.18 TEXAS INSTRUMENTS INC

AI summary

Methods and apparatus for a self-tracking high-side pre-driver control are described. In an example, a method is described comprising charging a first terminal associated with a first capacitive element to a first voltage with respect to ground and a second terminal associated with a second capacitive element to a second voltage with respect to ground, changing the first voltage and the second voltage with respect to ground by changing a swing voltage, selecting one of the first voltage or the second voltage based on a first switched-mode power supply topology or a second switched-mode power supply topology and driving a transistor using the selected voltage.