Switching Driver Circuitry for High-Voltage Stress Reduction

Solution Overview

Problem

Existing switching driver circuits face challenges in generating high-amplitude drive signals with reduced voltage stress across switches and minimizing current ripple and electromagnetic interference (EMI), particularly when operating with high input voltages.

Innovation Solution

The switching driver circuit operates in multiple modes with varying switching voltages, using an n-well switching block to connect the n-well of output switches to either the switching voltage node or a separate ground node, depending on the mode, thereby reducing voltage stress and current leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If high input voltages are used to generate high-amplitude drive signals, then the output voltage range is improved, but the voltage stress across switches increases and current ripple increases

Engineering Contradiction:

Improveoutput voltage rangeVSAvoidvoltage stress across switches

Core Design Contradiction:

PowerVSStress or pressure

Solution Approach 1:

The switching driver is divided into multiple independent switching stages, each operating at a lower voltage level. The first switching stage operates between ground and a first voltage level, while the second switching stage operates between the first voltage level and a second voltage level. This segmentation allows the overall system to achieve high output voltage range without subjecting individual switches to high voltage stress.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A first voltage level is introduced as an intermediary between ground and the second voltage level. This intermediate voltage node serves as a buffer, allowing switches to operate at lower voltage differences while still achieving the required overall voltage range. The intermediary voltage level reduces the voltage stress on individual switches and minimizes current ripple.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If high input voltages are used to generate high-amplitude drive signals, then the output voltage range is improved, but EMI increases

Engineering Contradiction:

Improveoutput voltage rangeVSAvoidEMI

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The switching driver is divided into multiple independent switching stages, each operating at a lower voltage level. The first switching stage operates between ground and a first voltage level, while the second switching stage operates between the first voltage level and a second voltage level. This segmentation allows the overall system to achieve high output voltage range without subjecting individual switches to high voltage stress.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A first voltage level is introduced as an intermediary between ground and the second voltage level. This intermediate voltage node serves as a buffer, allowing switches to operate at lower voltage differences while still achieving the required overall voltage range. The intermediary voltage level reduces the voltage stress on individual switches and minimizes current ripple.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If high input voltages are used to generate high-amplitude drive signals, then the output voltage range is improved, but the requirement for high-voltage tolerant switches increases

Engineering Contradiction:

Improveoutput voltage rangeVSAvoidswitch voltage tolerance requirements

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The switching driver is divided into multiple independent switching stages, each operating at a lower voltage level. The first switching stage operates between ground and a first voltage level, while the second switching stage operates between the first voltage level and a second voltage level. This segmentation allows the overall system to achieve high output voltage range without subjecting individual switches to high voltage stress.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The voltage operating parameters of individual switches are changed from high voltage to lower voltage levels. By distributing the voltage range across multiple stages, each switch operates within standard voltage tolerances, making the circuit more practical and cost-effective while still achieving the required overall output voltage range.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11469753B1Switching driver circuitry

Publication Date: 2022.10.11 CIRRUS LOGIC INC

AI summary

A switching driver circuit may have an output stage having an output switch connected between a switching voltage node and an output node. A switch network may control a switching voltage at the switching voltage node so that in one mode the switching voltage node is coupled to a positive voltage and in another mode the switching voltage node is coupled to ground voltage via a first switching path of the switch network. The circuit may also include an n-well switching block operable to, when the first switching voltage node is coupled to a positive voltage, connect the n-well of the first output switch to the switching voltage node, and, when the first switching voltage node is coupled to the ground voltage, connect the n-well of the first output switch to a first ground which is separate to the first switching voltage node and independent of the first switching path.