Internal Voltage Generator with Variable Channel Length

Solution Overview

Problem

Existing internal voltage generators in semiconductor memory devices fail to stably detect internal voltage levels during stand-by operation modes, especially under temperature variations, leading to erroneous operations and excessive current consumption.

Innovation Solution

Incorporating a temperature detecting unit that generates a bias voltage varying with temperature changes, combined with an internal voltage detecting unit that uses a reference voltage to output an internal voltage pumping signal, ensuring stable voltage detection and compensating for current driving capability in stand-by modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a second current sink unit NM2 with a longer channel is used in stand-by mode to reduce current consumption, then current consumption is reduced, but the threshold voltage rises causing the differential amplifier to fail to operate smoothly

Engineering Contradiction:

Improvecurrent consumptionVSAvoiddifferential amplifier operation reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the channel length of the current sink unit variable rather than fixed. The channel length adapting unit dynamically adjusts the channel length of the second current sink unit NM2 based on operating conditions (stand-by vs active mode), allowing the transistor to have a longer channel in stand-by mode for reduced current consumption, and a shorter effective channel in active mode for proper differential amplifier operation.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the internal voltage generating unit operates continuously due to erroneous detection, then voltage generation continues, but excessive current consumption occurs

Engineering Contradiction:

Improvevoltage detection accuracyVSAvoidcurrent consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements feedback through the channel length adapting unit that monitors the operating mode of the semiconductor memory and adjusts the channel length of the current sink unit accordingly. This feedback mechanism ensures that the differential amplifier receives appropriate bias conditions for accurate voltage detection in both stand-by and active modes, preventing erroneous detection that would lead to continuous operation and excessive current consumption.

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If the threshold voltage of the second current sink unit rises in stand-by mode, then current consumption is reduced, but the differential amplifier cannot operate smoothly leading to detection failure

Engineering Contradiction:

Improvecurrent consumptionVSAvoidinternal voltage level detection precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the channel length of the current sink unit variable rather than fixed. The channel length adapting unit dynamically adjusts the channel length of the second current sink unit NM2 based on operating conditions (stand-by vs active mode), allowing the transistor to have a longer channel in stand-by mode for reduced current consumption, and a shorter effective channel in active mode for proper differential amplifier operation.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7777560B2Internal voltage generator

Publication Date: 2010.08.17 MIMIRIP LLC

AI summary

An internal voltage generator includes an internal voltage detecting unit that receives an active signal activated in an active operation mode of a semiconductor memory and a bias voltage varying according to temperature variation, detects a level of an internal voltage by using a reference voltage and outputs an internal voltage pumping signal activated according to the level of the internal voltage.