Capacitor-Loop Level Shifter for Single-Supply Voltage Domain Conversion

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Solution Overview

Problem

The existing semiconductor integrated circuits face challenges with multiple voltage domains requiring separate power supplies for level shifter devices, leading to increased component count, reduced available space, and increased complexity and cost due to the need for multiple power supply interconnections.

Innovation Solution

A novel single supply level shifter circuit that uses a capacitor loop circuit and a complementary metal-oxide-semiconductor (CMOS) inverter to convert voltage signals between different voltage domains, eliminating the need for multiple power supplies by charging and discharging capacitors to facilitate voltage shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple voltage power supplies are used for level shifter devices in multi-voltage domains, then voltage conversion between domains is enabled, but the total number of components increases and available space decreases

Engineering Contradiction:

Improvevoltage conversion capabilityVSAvoidavailable space

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple power supply functions into a single voltage power supply by introducing a capacitor loop circuit that generates additional voltage domains through capacitive coupling and switching operations, thereby reducing the number of physical power supply connections needed while maintaining multi-voltage domain functionality

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The capacitor loop circuit acts as an intermediary between the single voltage power supply and the level shifter devices, generating the necessary voltage differences through capacitive charge transfer and switching, eliminating the need for direct multiple power supply connections

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple voltage power supplies are connected to level shifter devices, then voltage domain interfacing is achieved, but power supply routing circuit congestion increases

Engineering Contradiction:

Improvevoltage domain interfacingVSAvoidpower supply routing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple power supply routing functions are merged into a single routing path by using one voltage power supply with a capacitor loop circuit that dynamically generates the required voltage domains, simplifying the power supply routing architecture and reducing congestion

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system transitions from static multiple power supply connections to a dynamic single power supply system with a capacitor loop circuit that adaptively generates voltage domains through switching operations, reducing routing complexity

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If multiple voltage power supplies are used for level shifting, then voltage conversion is enabled, but manufacturing cost and design complexity increase

Engineering Contradiction:

Improvelevel shifting functionalityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple power supply requirements into a single power supply with a capacitor loop circuit, reducing the bill of materials and assembly complexity, thereby lowering manufacturing costs while maintaining level shifting functionality

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single voltage power supply with capacitor loop circuit performs multiple functions including power supply, voltage domain generation, and level shifting support, eliminating the need for separate dedicated power supplies for each voltage domain

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution reduces the number of components needed, decreases the complexity of power supply routing, and lowers manufacturing costs by enabling efficient up/down voltage shifting with a single power supply, thereby optimizing space and reducing the slew rate of output signals.

Implementation Method 1

a capacitor loop circuit associated with the first circuit, the level shifter circuit and the voltage source and configured with a capacitor to charge from at least one of a first circuit output voltage and a voltage source output voltage and to discharge into a specified node of the level shifter circuit

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS7750717B2Single supply level shifter circuit for multi-voltage designs, capable of up/down shifting

Publication Date: 2010.07.06 TEXAS INSTRUMENTS INC

AI summary

A method, system, and apparatus to a novel single supply level shifter circuit for multi-voltage designs, capable of up/down shifting are disclosed. In one embodiment, a system includes a first circuit, a second circuit, a voltage source with an output voltage equal to a voltage value of the second circuit, a level shifter circuit coupled with both an output of the first circuit and an output of the voltage source and wherein the level shifter circuit is used to convert a voltage value of a signal from the first circuit to the voltage value of the second circuit, and a capacitor loop circuit associated with the first circuit, the level shifter circuit and the voltage source and configured with a capacitor to charge from at least one of a first circuit output voltage.