Bidirectional Current Sense Circuit with Disabling Mechanism

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Solution Overview

Problem

Battery-operated devices face energy consumption issues due to circuits used to monitor battery usage, as these circuits draw power even when the device is in low power mode or not in use, leading to unnecessary current flow.

Innovation Solution

Implementing bidirectional current sense circuits that can be disabled by de-coupling feedback paths and disabling the input stage of the operational amplifier to reduce current flow during periods of inactivity, using electrically controlled switches and switch control circuits to manage power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the current sense circuit remains active to monitor battery usage, then battery monitoring function is maintained, but energy consumption increases

Engineering Contradiction:

Improvebattery monitoring functionVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The current sense circuit transitions between active and low-power states dynamically based on operational needs. The operational amplifier is disabled by disconnecting its input stage during low-power modes, while enabling it during active usage, allowing the system to adapt its power consumption to actual monitoring requirements

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The circuit periodically enables the operational amplifier to perform monitoring functions only when necessary, rather than maintaining continuous operation. This periodic activation aligns with battery charging/discharging cycles, reducing overall energy consumption while maintaining monitoring reliability

Inventive Principle:

Principle #19Periodic action

2Use of energy by moving object

If the operational amplifier is disabled to reduce current flow, then energy consumption decreases, but the ability to monitor bidirectional current is lost

Engineering Contradiction:

Improvecurrent flowVSAvoidcurrent monitoring capability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

Feedback paths are pre-configured with switch elements that can rapidly connect or disconnect based on operational mode. This preliminary arrangement of control paths allows the circuit to quickly transition between monitoring and low-power states without delay, maintaining both energy efficiency and monitoring readiness

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The circuit uses feedback mechanisms to detect when current monitoring is required and automatically enables the operational amplifier accordingly. This feedback-driven control ensures the amplifier operates only when actual monitoring is needed, balancing energy consumption with monitoring capability

Inventive Principle:

Principle #23Feedback

3Measurement precision

If feedback paths are connected to maintain operational accuracy, then measurement precision is improved, but current consumption increases

Engineering Contradiction:

Improvecurrent sensing accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The feedback paths are extracted or disconnected from the operational amplifier during low-power modes by using switch elements. This extraction eliminates unnecessary current flow through the feedback networks while preserving the ability to reconnect them when measurement precision is required

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Different parts of the current sense circuit have different operational states - the operational amplifier and feedback paths are disabled during low-power modes while other circuit components remain active. This localized control allows precision components to be powered down when not needed, reducing overall power consumption

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10802079B2System and method for bidirectional current sense circuits

Publication Date: 2020.10.13 SEMICON COMPONENTS IND LLC

AI summary

Operating current sense circuits. At least some of the example embodiments are methods including: sensing a current flow through a sense resistor by way of an operational amplifier defining a non-inverting input coupled to a first side of the sense resistor and an inverting input coupled to a second side of the sense resistor; driving a signal to a sense output of the operational amplifier, the signal proportional to the current flow through the sense resistor; and then disabling the current sense circuit comprising: de-coupling a first feedback path of the operational amplifier, the first feedback path coupled to the non-inverting input; and de-coupling a second feedback path of the operational amplifier, the second feedback path coupled to the inverting input. The methods also include disabling the current sense circuit by disabling an input stage of the operational amplifier.