IGBT Junction Temperature Correction via Diode Calibration
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Solution Overview
Problem
Conventional IGBT temperature sensors face errors due to semiconductor process variations, leading to inaccurate temperature estimation and potential thermal destruction risks, especially in electric vehicles and hybrid vehicles, which can compromise driver safety.
Innovation Solution
An IGBT temperature sensor correction apparatus and method that adjusts diode current based on the resistance value of an internal resistor to correct voltage values, using a driver integrated circuit and an external resistor to mitigate errors caused by semiconductor process variations, thereby improving temperature sensing precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional NTC-type temperature sensor is used on the DBC, then the temperature sensing structure is simple, but the temperature measurement accuracy deteriorates due to monitoring coolant temperature instead of actual junction temperature
Solution Approach 1:
The patent introduces a polysilicon diode as an intermediary sensing element integrated directly onto the IGBT chip. This diode serves as a mediator that directly experiences the junction temperature, converting thermal information into voltage signals that can be measured, thereby achieving accurate junction temperature monitoring without directly measuring the difficult-to-access thermal field
2Measurement precision
If a polysilicon diode is integrated onto the IGBT chip for direct temperature detection, then the temperature measurement accuracy is improved, but the measurement precision deteriorates due to semiconductor process variations
Solution Approach 1:
The patent implements a feedback mechanism where the voltage-temperature characteristics of the polysilicon diode are continuously monitored and used to adjust compensation parameters. The system measures the diode voltage at different temperatures, establishes a calibration curve, and uses this feedback information to compensate for process variations, thereby maintaining consistent temperature sensing across different semiconductor batches
Solution Approach 2:
The patent changes the operating parameters of the polysilicon diode by applying different current levels and measuring voltage responses at various temperatures. By varying these electrical parameters and establishing the relationship between voltage, current, and temperature, the system compensates for process variations and achieves reliable temperature measurement
3Ease of operation
If temperature sensing deviation is not corrected, then the device operation is simple, but the safety deteriorates due to thermal destruction risk
Solution Approach 1:
The patent performs preliminary temperature sensing calibration and compensation parameter establishment before actual operation. By pre-characterizing the polysilicon diode's voltage-temperature characteristics and storing compensation data in memory, the system prepares safety correction mechanisms in advance, ensuring accurate temperature monitoring and driver protection without complicating real-time operation
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
The solution effectively corrects temperature sensing errors, prevents overheating, and extends the maximum output current range of motor drives, ensuring driver safety and increasing the maximum output range of motors by minimizing design margins.
Implementation Method 1
integrates a polysilicon diode onto an IGBT chip and thus directly detects an IGBT temperature using voltage-temperature characteristics of the polysilicon diode
Implementation Method 2
A power source and a resistor may be connected to an input terminal of the diode such that a predetermined current can flow in the input terminal of the diode
Data Source
AI summary
An Insulated Gate Bipolar Transistor (IGBT) temperature sensor correction apparatus includes an Insulated Gate Bipolar Transistor (IGBT); a temperature sensor having a sensing diode; and a process variation sensor having an internal resistor.