Electronic Switching Module With Opposite-Type Leakage Compensation

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Solution Overview

Problem

Existing electronic switching modules suffer from inaccuracies due to injected charges causing errors and voltage drift, which affect precision in digital-to-analog and analog-to-digital conversions, and current leakage through compensation transistors.

Innovation Solution

Incorporating an output compensation transistor with a different conductivity type to reduce leakage currents and an intermediate compensation transistor to stabilize the sampled voltage, along with control signals to manage these transistors, thereby maintaining a constant sampled voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a compensation transistor with the same conductivity type as the main switching transistor is used, then charges injected by parasitic capacitance can be compensated, but additional leakage current occurs and sampled voltage drifts over time

Engineering Contradiction:

Improvecompensation of injected chargesVSAvoidleakage current and voltage drift

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies inversion by using a compensation transistor with opposite conductivity type (PMOS instead of NMOS) compared to the main switching transistor. This reversed approach eliminates the leakage current problem while maintaining charge compensation capability, as the opposite conductivity type prevents the formation of leakage paths that occur with same-type transistors.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the conductivity type parameter of the compensation transistor from matching the main switching transistor (same type) to being opposite (different type). This parameter change fundamentally alters the electrical characteristics, eliminating leakage current while preserving the charge compensation function through different physical mechanisms.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the main switching transistor transfers the input reference voltage to the output, then the sampled voltage is delivered, but injected charges alter the sampled voltage relative to the input reference voltage

Engineering Contradiction:

Improvevoltage transfer capabilityVSAvoidsampled voltage accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The compensation transistor acts as an intermediary element between the main switching transistor and the output. It mediates the charge transfer process by compensating for injected charges through its opposite conductivity type, thereby maintaining the accuracy of the sampled voltage while allowing the main transistor to perform its voltage transfer function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The compensation transistor provides a feedback mechanism that counteracts the charge injection effects of the main switching transistor. By being controlled in coordination with the main transistor, it creates a negative feedback effect that cancels out the harmful charge injection, preserving voltage accuracy during the transfer process.

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

The solution effectively reduces errors and voltage drift, ensuring precise voltage transfer independently of production methods, threshold voltages, and temperature variations, enhancing the accuracy of the sampled voltage.

Implementation Method 1

an output compensation transistor arranged between the main switching transistor and said output, the output compensation transistor having a channel having a second type of conductivity, the output compensation transistor being configured to reduce a leakage current to or from the output terminal

Methodology Applied

Scientific EffectLeakage current reduction through different conductivity type:

Implementation Method 2

a main switching transistor connected to the input and output, the main switching transistor having a channel having said first type of conductivity

Methodology Applied

Scientific EffectVoltage transfer through switching transistor:

Implementation Method 3

During a sample phase, delivers this voltage to a capacitor connected to its output terminal. During a hold phase, the electronic switching module is blocked and the output voltage is maintained by discharging the capacitor

Methodology Applied

Scientific EffectCapacitive energy storage and discharge: Capacitance

Data Source

PatentUS20250337405A1Electronic switching module and method of controlling such a module

Publication Date: 2025.10.30 STMICROELECTRONICS INT NV

AI summary

Provided is an electronic switching module including an input switching transistor connected to an input. The input switching transistor having a channel having a first type of conductivity. The electronic switching module includes a first switching transistor arranged between the input switching transistor and an output. The first switching transistor having a channel having said first type of conductivity. The electronic switching module includes an output compensation transistor disposed between the first switching transistor and said output. The output compensation transistor has a channel having a second type of conductivity, and the output compensation transistor is configured to reduce a leakage current to or from the output terminal.