Isolated ECU Power Converter Control Without Extra Switching Converters
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Solution Overview
Problem
Existing automotive High Voltage (HV) Electronic Control Units (ECUs) require additional switching converters for galvanic isolation, which are cost-inefficient and unnecessary, as they need separate primary and secondary supplies for digital isolators to enable high baud rate communication between high voltage and low voltage domains.
Innovation Solution
An ECU design that includes a high voltage domain and a low voltage domain with galvanic isolation, utilizing a DC/DC converter in the high voltage domain to generate output voltage from a battery voltage and an isolation device to enable communication, eliminating the need for additional switching converters by using a Switched-Mode Power Supply (SMPS) to transfer power across the isolation barrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If digital isolators with capacitors or coreless transformers are used to enable galvanic isolation for high baud rate communication, then communication capability between HV and LV domains is improved, but additional switching converters are required to provide separate primary and secondary supplies, increasing device complexity and cost
Solution Approach 1:
The patent merges the power conversion function into the existing DC/DC converter that is already present in the HV domain for battery voltage conversion. This converter is enhanced to also provide galvanic isolation for digital communication by integrating isolation functionality, thereby eliminating the need for separate switching converters while maintaining reliable high baud rate communication between HV and LV domains
2Reliability
If separate external switching converter is used to provide isolated primary and secondary supplies for digital isolators, then galvanic isolation for communication is achieved, but system cost and complexity increase
Solution Approach 1:
The DC/DC converter in the HV domain is designed to perform multiple functions: it converts battery voltage to appropriate voltage levels for HV domain components and simultaneously provides galvanic isolation for digital communication between domains. This multi-functional design eliminates the need for separate dedicated isolation converters, reducing overall system complexity while maintaining reliable galvanic isolation
3Reliability
If additional switching converters are added to existing HV-ECU architecture, then power supply for digital isolators is provided, but manufacturing cost and system complexity increase
Solution Approach 1:
The patent combines the power supply function and galvanic isolation function into a single enhanced DC/DC converter unit. By integrating these functions, the system avoids the need for additional separate converters, thereby reducing component count, simplifying manufacturing processes, and lowering overall system cost while maintaining the required power supply capability for digital isolators
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 efficient and cost-effective communication between high voltage and low voltage domains without the need for additional switching converters, reducing system complexity and cost while maintaining the ability to transition between Sleep Mode and Normal Operation in response to enable signals.
Implementation Method 1
a DC/DC converter in the high voltage domain which is configured to receive a first battery voltage and to generate an output voltage therefrom for supplying the controller
Implementation Method 2
digital isolators are commonly used by circuit designers which usually include capacitors or coreless transformers to accomplish the galvanic isolation
Implementation Method 3
digital isolators are commonly used by circuit designers which usually include capacitors or coreless transformers to accomplish the galvanic isolation
Data Source
AI summary
In accordance with an embodiment, an electronic control unit (ECU) includes: a high voltage domain and a low voltage domain galvanically isolated from each other; a bus interface circuit in the low voltage domain; a controller in the high voltage domain, the controller being configured to receive data from and transmit data to the bus interface circuit; a first isolation device that couples the controller and the bus interface circuit; a DC/DC converter in the high voltage domain configured to receive a first battery voltage and configured to generate an output voltage therefrom for supplying the controller; and a second isolation device configured to receive an enable signal from a first circuit node in the low voltage domain and to provide the enable signal to the DC/DC converter in the high voltage domain.