Bootstrap Circuit Initial Gate Boost Against Parasitic Capacitance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional bootstrap circuits face challenges due to parasitic capacitance at output nodes, which can prevent the booting voltage from reaching the desired level, affecting the operation of subsequent circuits.

Innovation Solution

A bootstrap circuit design that includes a receiving circuit, a switched capacitor module, and a booting circuit, where the booting circuit applies an initial voltage to the transistor's gate electrode when the control signal starts, enhancing the voltage level of the control signal and mitigating the impact of parasitic capacitance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional bootstrap circuit uses a switched capacitor to generate booting voltage, then the circuit structure is simple, but parasitic capacitance at output nodes prevents the booting voltage from reaching the desired level

Engineering Contradiction:
Improvecircuit structureVSAvoidbooting voltage level
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The bootstrap circuit is divided into distinct functional modules: a switched capacitor module for voltage generation, a receiving circuit for signal reception, and a booting circuit for voltage boosting. This segmentation allows each module to be optimized independently, with the booting circuit specifically designed to compensate for parasitic capacitance effects and ensure the control signal reaches the desired voltage level.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The booting circuit applies an initial voltage to the transistor gate electrode before the control signal fully activates, preparing the transistor for optimal operation. This preliminary action ensures that when the control signal arrives, the transistor is already in a state that minimizes the impact of parasitic capacitance, allowing the booting voltage to reach the target level accurately.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If parasitic capacitance is present at output nodes, then the circuit operation is influenced negatively, but adding compensation circuits increases device complexity

Engineering Contradiction:
Improvecircuit operationVSAvoidcircuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The booting circuit is integrated with the switched capacitor module and receiving circuit to form a unified bootstrap circuit. The booting circuit combines voltage generation, signal reception, and voltage boosting functions in a coordinated manner, reducing the need for separate compensation circuits while maintaining reliable operation despite parasitic capacitance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The booting circuit automatically detects and compensates for voltage level deficiencies caused by parasitic capacitance without requiring external intervention or complex control mechanisms. The circuit self-regulates to ensure the control signal reaches the desired level, maintaining reliability while keeping the overall structure relatively simple.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the control signal voltage level is insufficient due to parasitic capacitance, then transistor switching performance deteriorates, but increasing voltage generation capability may cause energy loss

Engineering Contradiction:
Improvetransistor switchingVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The booting circuit operates periodically, applying initial voltage boosts only when needed during transistor switching transitions. This periodic action ensures optimal transistor switching performance by providing voltage support at critical moments while avoiding continuous energy consumption that would occur with constant voltage generation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The booting circuit dynamically adjusts voltage parameters based on the operating state of the transistor and the magnitude of parasitic capacitance effects. By changing voltage levels adaptively rather than maintaining a constant high voltage, the circuit achieves good transistor switching performance while minimizing energy loss during non-critical periods.

Inventive Principle:
Principle #35Parameter changes

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 improves the linearity and signal quality of the output signal, making it more suitable for subsequent circuits by ensuring the control signal reaches the desired level, thereby enhancing the performance of the bootstrap circuit.

Implementation Method 1

parasitic capacitance at output nodes of the switched capacitor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

the booting circuit is coupled to the receiving circuit, and is arranged for applying an initial voltage when the control signal starts to enable the transistor, to increase a voltage level of the control signal

Methodology Applied
Scientific EffectVoltage boosting:

Data Source

PatentEP3573235B1Initial booting bootstrap circuit and associated analog-to-digital converter
Publication Date: 2022.08.10 MEDIATEK INC
  • EP3573235B1 patent drawingFigure 1~2
  • EP3573235B1 patent drawingFigure 3
  • EP3573235B1 patent drawingFigure 4

AI summary

A bootstrap circuit (100) including a receiving circuit (110), a switched capacitor module (120) and a booting circuit (130) is provided. The receiving circuit receives an input signal (Vin) to selectively output an output signal (Vout) according to a control signal (Vc'). The switched capacitor module is coupled to the input signal, and is arranged for generating the control signal (Vc) according to the input signal. The booting circuit is coupled to the receiving circuit, and is arranged for applying an initial voltage (Vib) when the control signal starts to enable the transistor, to increase a voltage level of the control signal.