Supply Voltage Detector Biasing for Fast Startup and Low Power

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Solution Overview

Problem

Designing a supply voltage detector for integrated circuits that is both power efficient and high-performance, especially during startup or transitions from standby mode, is challenging due to the need for rapid detection of supply voltage levels without excessive power consumption.

Innovation Solution

A supply voltage detector with a comparator and startup current boosters that generate supplemental currents during supply voltage ramp-up, allowing rapid operation without excess power consumption once the steady-state voltage is reached, and a bias voltage generator providing multiple bias voltages to facilitate accurate voltage detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a supply voltage detector is designed to operate rapidly during startup when supply voltage is ramping up quickly, then detection speed is improved, but power consumption increases

Engineering Contradiction:
Improvedetection speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the comparator's operating state adjustable based on supply voltage conditions. The comparator transitions between a first operating state during startup (fast response, higher power) and a second operating state during normal operation (standard response, lower power). This dynamic adaptation resolves the contradiction by optimizing both speed and power consumption according to operational phase.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the comparator's operating parameters (power consumption level and response speed) based on the supply voltage state. During startup when supply voltage is ramping up, the comparator operates in a first state with higher power consumption and faster response. Once supply voltage stabilizes, it switches to a second state with lower power consumption and standard response speed. This parameter change strategy resolves the speed-power contradiction.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If a supply voltage detector is designed to be power efficient during normal operation, then power consumption is reduced, but detection speed may be insufficient during rapid voltage changes

Engineering Contradiction:
Improvepower consumptionVSAvoiddetection speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The patent implements dynamic operation mode switching that adapts the comparator's performance characteristics to operational requirements. During normal operation, the comparator runs in a power-efficient mode with standard response speed. During startup or rapid voltage transitions, it automatically switches to a high-speed mode with higher power consumption. This dynamic approach ensures power efficiency is maintained during normal operation while detection speed is available when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the comparator's operational parameters based on supply voltage conditions. The system monitors supply voltage state and adjusts the comparator's power consumption and response speed accordingly. This parameter adaptation allows the system to achieve power efficiency during stable operation while maintaining the capability for fast detection during critical transitions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the comparator operates continuously at high speed to ensure rapid detection, then detection performance is improved, but overall power consumption increases

Engineering Contradiction:
Improvedetection performanceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by implementing variable operating modes for the comparator based on system state. Rather than continuous high-speed operation, the comparator dynamically switches between a first operating state (faster, higher power) during startup/critical phases and a second operating state (standard speed, lower power) during normal operation. This ensures detection performance is maintained when critical while minimizing power consumption during stable operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the comparator's operational parameters (speed and power consumption) according to supply voltage state and operational phase. This parameter modulation ensures that high detection performance is achieved only when necessary (during startup or rapid voltage changes), while power consumption is reduced during normal stable operation, thus resolving the reliability-power contradiction.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4471438A1Integrated circuit with supply voltage detector
Publication Date: 2024.12.04 STMICROELECTRONICS INT NV
  • EP4471438A1 patent drawingFigure 1
  • EP4471438A1 patent drawingFigure 2A
  • EP4471438A1 patent drawingFigure 2B

AI summary

A supply voltage detector (102) of an integrated circuit (100) is able to detect the state of a supply voltage (Vdd) upon startup with both high-speed and low overall power consumption. The supply voltage detector (102) includes a comparator (106) that generates an output voltage (Vout) based on the current state of the supply voltage (Vdd). The comparator (106) includes a startup current booster (112, 114) that generates a supplemental current for the comparator (106) while the supply voltage (Vdd) is ramping up. The startup current booster (112, 114) stops generating the supplemental current when the supply voltage (Vdd) reaches the expected steady-state value or a selected fraction or portion of the expected steady-state value.