E-Fuse Driver Interface for Loss-of-Ground Protection Testing
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Solution Overview
Problem
Conventional push-pull drivers for electronic fuses cannot produce a gate voltage below the ground voltage, leading to insufficient protection during loss of ground conditions, making it impossible to reliably test the e-fuse's functionality in automotive environments.
Innovation Solution
An interface circuit is introduced between the driver and the electronic fuse, incorporating a switch that couples the control input to the test load ground in response to a voltage difference, ensuring the e-fuse blocks current flow during loss of ground events, and includes diodes to manage reverse polarity scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional push-pull driver is used to drive the MOSFET gate, then the driver circuit is low-cost and highly efficient, but the driver cannot produce a gate voltage below ground voltage, causing insufficient protection during loss of ground conditions
Solution Approach 1:
An interface circuit is introduced as an intermediary between the push-pull driver and the MOSFET gate. This interface includes a switch (such as a transistor) that couples the gate to the test load ground when a voltage difference is detected, enabling the gate voltage to go below ground potential during loss of ground events without modifying the simple push-pull driver architecture.
2Stability of the object's composition
If the driver ground voltage floats above the test load ground voltage during loss of ground events, then the driver operates normally within its supply range, but the low-state gate voltage becomes insufficient to turn off the MOSFET, exposing the test load to excessive current
Solution Approach 1:
The interface circuit proactively counteracts the harmful effect of floating driver ground by detecting the voltage difference between driver ground and test load ground. When the driver ground floats above test load ground, the interface switch activates to pull the gate voltage below test load ground potential, preemptively preventing excessive current flow before damage can occur to the test load.
3Reliability
If additional interface circuitry is added to enable loss of ground testing, then protection reliability under loss of ground conditions is improved, but the device complexity and component count increase
Solution Approach 1:
The interface circuit utilizes the existing voltage difference between driver ground and test load ground as its own control signal. The switch in the interface is automatically controlled by this voltage difference without requiring external control logic or additional sensing circuits, allowing the interface to self-regulate and enable loss of ground protection using minimal components.
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 reliable testing of e-fuse functionality under loss of ground and reverse polarity conditions, protecting the test load from excessive current and power dissipation, while using minimal components and maintaining cost-effectiveness.
Implementation Method 1
the switch is responsive to a voltage difference between a ground of the driver and the ground of the test load to switch the control input such that the electronic fuse blocks current
Implementation Method 2
includes diodes to manage reverse polarity scenarios
Data Source
AI summary
An electronic fuse driver interface having a circuit arranged to couple to a driver, an electronic fuse, and a test load. The interface includes a switch configured to selectively couple a control input of the electronic fuse to a ground of the test load. The interface includes a resistor network between the ground of the test load and a ground of the driver. The switch is connected to the resistor network to switch the control input such that the electronic fuse selectively blocks current between a test supply voltage and the test load. The interface includes a diode connected between an intermediate node of the resistor network and the test supply voltage to provide a path between the ground of the test load and the test supply voltage.