Power Module Sense Transistor Crosstalk Compensation

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Solution Overview

Problem

In electronic devices with multiple power modules on a semiconductor substrate, crosstalk occurs due to disproportionate load currents between adjacent power modules, leading to erroneous sense current values and inaccurate load current calculations.

Innovation Solution

The use of two strategically positioned sense transistors within each power module to offset the crosstalk effect, where one sense transistor's current is increased and the other's is decreased by equal magnitude, allowing the measurement circuit to calculate a more accurate load current by compensating for the crosstalk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple power modules are integrated on a semiconductor substrate, then power delivery capability is improved, but crosstalk between adjacent modules increases causing measurement errors

Engineering Contradiction:

Improvepower delivery capabilityVSAvoidsense current accuracy

Core Design Contradiction:

PowerVSMeasurement precision

Solution Approach 1:

The sense transistor is divided into two separate sense transistors positioned at different locations within the power module. Each sense transistor samples the sense current at a different position, allowing the measurement circuit to detect and compensate for crosstalk effects by comparing the two measurements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The measurement circuit acts as an intermediary that processes the sense current measurements from both sense transistors. It calculates a corrected sense current value by compensating for the crosstalk effect detected through the differential measurement, thereby eliminating measurement errors caused by adjacent power modules.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If sense transistors are positioned closer to adjacent power modules, then crosstalk effect is enhanced for measurement, but measurement circuit complexity increases

Engineering Contradiction:

Improvecrosstalk detection accuracyVSAvoidmeasurement circuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The measurement circuit changes the measurement parameter by taking the difference or ratio between the two sense current measurements. This mathematical transformation allows the circuit to extract crosstalk information without requiring complex additional hardware, maintaining simplicity while achieving accurate crosstalk detection.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11152341B2Power module including a power transistor and two sense transistors

Publication Date: 2021.10.19 TEXAS INSTRUMENTS INC

AI summary

In some examples, an integrated circuit includes a plurality of power modules formed on a substrate, including a first power module located between second and third power modules. The first power module is configured to conduct a load current, and includes a power transistor and first and second sense transistors. The first sense transistor is disposed at a first position between the second power module and a central axis of the first power module, and the second sense transistor is disposed at a second position between the third power module and the central axis. The first sense transistor is configured to conduct a first sense current; and the second sense transistor is configured to conduct a second sense current. The first and second sense transistors are configured to direct the first and second sense currents toward a measurement circuit that is configured to determine a derived sense current indicative of the load current.