High Side Driver Without Dedicated Supply Pin
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Solution Overview
Problem
Existing DC-to-DC power converters require a dedicated supply for high side switches, which increases component count, area, and cost, and often necessitate additional pin counts in control ICs, complicating the minimization of power supply form factor.
Innovation Solution
A DC-to-DC converter design that integrates a highside switch and lowside switch with a diode and capacitor, utilizing an integrated circuit to generate control signals and eliminate the need for a dedicated pin for the high side supply, allowing operation within a wide input voltage range without additional driver components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated supply circuitry is used for the high side switch, then the high side switch can be driven properly, but the component count and area increase
Solution Approach 1:
The patent combines the high side supply function with existing control IC pins (half bridge pin, high side gate control pin) that would otherwise be unused or underutilized. By merging the bootstrap capacitor connection to the half bridge pin and the high side supply connection to the high side gate control pin, the dedicated supply circuitry is integrated into the control IC's existing structure, eliminating external dedicated supply components while maintaining proper high side switch drive capability
Solution Approach 2:
The control IC pins are assigned multiple functions: the half bridge pin serves both as a control signal output and as a connection point for the bootstrap capacitor, while the high side gate control pin serves both as a gate drive output and as a connection point for the high side supply. This multi-functionality eliminates the need for separate dedicated supply pins and external components
2Reliability
If additional pins are added to the control IC for dedicated supply, then the high side switch can be driven, but the pin count increases
Solution Approach 1:
The patent merges the dedicated supply function with existing control pins by connecting the bootstrap capacitor to the half bridge pin and the high side supply to the high side gate control pin. This integration allows the control IC to provide high side drive capability using its existing pin structure without requiring additional dedicated supply pins
3Reliability
If a booststrap supply circuitry with diode and capacitor is used, then the high side switch can be driven, but the component count increases
Solution Approach 1:
The patent extracts the essential function of the bootstrap supply (storing energy to drive the high side switch) and implements it using only the minimum necessary components: a single bootstrap capacitor connected between the half bridge pin and ground, and utilizing the control IC's internal circuitry to provide the diode function and voltage regulation, thereby eliminating redundant external components
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 design reduces the component count and area requirements, minimizing the power supply form factor and cost while maintaining efficient operation across a wide input voltage range, from 8V to 400V, without the need for a separate driver supply for the high side switch.
Implementation Method 1
a capacitor, coupled between a half bridge pin and a ground pin of the driver integrated circuit
Implementation Method 2
a diode coupled between a high side supply pin and the half bridge pin
Data Source
AI summary
A DC-to-DC converter is disclosed. The SMPS driver includes a highside switch having a first terminal, a second terminal and a gate. The first terminal is coupled to an input voltage terminal. The SMPS driver further includes a lowside switch having a first terminal, a second terminal and a gate. The first terminal of the lowside switch is coupled to the second terminal of the highside switch and the second terminal of the lowside switch is coupled to ground. A diode is coupled to the gate of the lowside switch on one side and to a capacitor on the other side. An integrated circuit (IC) is included to generate control signals for switching the highside switch and the lowside switch. The IC includes a highside supply pin, a highside gate control pin, a half bridge pin, a lowside gate control pin and a ground pin. The gate of the lowside switch is coupled to the lowside gate control pin, the highside supply pin is coupled to the diode and the capacitor is coupled to the half bridge pin.