Semiconductor Chip Wiring Layout for Current Sensing Without Extra Pads
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Solution Overview
Problem
Existing semiconductor devices face challenges in efficiently detecting output current flowing through power transistors due to the need for dedicated wires and pads for current detection, which affects area efficiency and on-resistance.
Innovation Solution
Integrating a sense resistor within the semiconductor chip and branching the current path to utilize metal wirings as sense resistors, allowing for current detection without dedicated wires and pads, thereby improving area efficiency and maintaining transistor layout symmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated wires and pads are used for current detection, then current detection capability is improved, but area efficiency deteriorates
Solution Approach 1:
The patent applies multi-functionality by making the metal wirings serve dual purposes: they function as both power supply paths and sense resistors for current detection. This eliminates the need for separate dedicated detection wires and pads, thereby improving area efficiency while maintaining current detection capability.
2Measurement precision
If dedicated wires and pads are used for current detection, then current detection capability is improved, but on-resistance increases
Solution Approach 1:
The metal wirings are designed to perform multiple functions simultaneously - serving as power supply conductors and as sense resistors for current detection. This integration eliminates the need for additional dedicated detection paths that would increase overall on-resistance, thereby maintaining low on-resistance while enabling accurate current detection.
3Measurement precision
If power transistor layout is adjusted for current detection, then current detection is enabled, but layout symmetry deteriorates
Solution Approach 1:
The patent enables current detection by utilizing existing metal wirings in the power transistor layout as sense resistors, rather than requiring separate detection paths. This approach maintains the original symmetric layout of the power transistors while enabling current detection functionality through the multi-use of existing wiring structures.
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
Enables effective current detection without dedicated wires and pads, enhancing area efficiency and maintaining low on-resistance of the power transistor.
Implementation Method 1
a wiring resistance component of the metal wiring serves as a sense resistor
Data Source
AI summary
Disclosed herein is a semiconductor chip including a power transistor, a plurality of pads, a plurality of wirings each configured to provide electrical continuity between each of the plurality of pads and one end of the power transistor, and a current detection circuit configured to detect, as a sense voltage, at least one of voltage drops occurring in the plurality of wirings, respectively, according to a shunt current flowing through each of the plurality of wirings and a wiring resistance component of each of the plurality of wirings.