Bootstrap Sampling Circuit With Protection Switches for Overvoltage

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Solution Overview

Problem

Bootstrap circuits face issues when sampling input signals higher than the power supply voltage, leading to potential destruction of sampling switches and current leakage due to voltage limitations.

Innovation Solution

Incorporating a sampler with a sampling switch and protection switches, along with a driver that controls the sampler based on control signals to perform pre-charge and sample operations, ensuring that the voltage applied to the sampling switch does not exceed its limit, using protection switches like NMOS transistors to prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a bootstrap circuit samples an input signal higher than the power supply voltage, then the sampling capability is improved, but the sampling switch may be destroyed or current leakage occurs

Engineering Contradiction:

Improvesampling capabilityVSAvoidswitch safety

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces protection switches (first protection switch and second protection switch) as intermediary components between the input signal and the sampling switch. These protection switches act as mediators that control the voltage applied to the sampling switch, preventing direct exposure to excessive input voltages while still allowing the sampling function to operate with high-voltage signals

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If protection switches are added to prevent sampling switch damage, then switch safety is improved, but device complexity increases

Engineering Contradiction:

Improveswitch safetyVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the protection function with the existing bootstrap circuit structure by integrating the first and second protection switches into the sampling path. The control logic for these protection switches is combined with the driver's existing control signals, allowing the protection mechanism to be implemented without adding separate complex control systems

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the driver controls voltage applied to the sampler, then switch safety is improved, but control complexity increases

Engineering Contradiction:

Improvevoltage controlVSAvoidcontrol logic

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The driver monitors the input signal voltage level and uses feedback control to adjust the state of the protection switches. When the input voltage exceeds safe levels, the driver automatically activates the protection switches to limit the voltage applied to the sampling switch, creating a self-regulating control mechanism

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20240146292A1Bootstrap circuit and communication device including the same

Publication Date: 2024.05.02 SAMSUNG ELECTRONICS CO LTD

AI summary

A bootstrap circuit for generating an output signal through a pre-charge operation and a sample operation, includes: a sampler including a sampling switch configured to sample an input signal, a first protection switch connected between an input node and the sampling switch, and a second protection switch connected between the sampling switch and an output node; and a driver configured to drive the sampler based on a power supply voltage and the input signal.