Negative Current Detection Circuit for Parasitic Latch-Up Prevention
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Solution Overview
Problem
Semiconductor devices used in automotive applications face malfunctions due to parasitic element malfunctions, leading to reduced power supply voltage and increased power consumption during transitions in inductive load operations, particularly when negative currents are detected without proper voltage management.
Innovation Solution
A negative current detection circuit is introduced, comprising a comparator, transistors, and resistors, which detects output voltage relative to ground voltage and switches between applying output voltage or ground voltage to a reference voltage, preventing parasitic element malfunctions and reducing power consumption by ensuring proper voltage alignment during transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the semiconductor device operates during transitions in inductive load operations, then the device can control the load, but parasitic element malfunctions occur leading to reduced power supply voltage and increased power consumption
Solution Approach 1:
The negative current detection circuit proactively detects negative current conditions before they cause parasitic element malfunctions. By detecting the output voltage relative to ground voltage and switching between applying output voltage or ground voltage to the reference voltage in advance, the circuit prevents power consumption increases during transitions.
Solution Approach 2:
The detection signal generating circuit continuously monitors the output voltage and provides feedback to the control circuit. This feedback mechanism allows the system to adjust the reference voltage dynamically, ensuring proper voltage alignment during transitions and preventing parasitic element malfunctions that would otherwise increase power consumption.
2Ease of operation
If the semiconductor device transitions between operating states, then the device can respond to control signals, but parasitic element malfunctions occur causing voltage instability
Solution Approach 1:
The negative current detection circuit acts as an intermediary between the control signals and the power supply voltage. By introducing this detection mechanism, the system can mediate transitions between operating states, ensuring that the reference voltage is properly aligned before switching occurs, thus maintaining voltage stability while preserving ease of operation.
Solution Approach 2:
Before transitioning between operating states, the detection circuit performs preliminary detection of the output voltage condition. This preliminary action ensures that the reference voltage is switched to the appropriate level (output voltage or ground voltage) in advance, preventing voltage instability during the transition while maintaining responsive operation.
3Device complexity
If no negative current detection circuit is present, then the device structure is simpler, but parasitic element malfunctions occur during negative current conditions
Solution Approach 1:
The negative current detection circuit serves as a protective intermediary that monitors output voltage conditions and prevents parasitic element malfunctions. This additional circuit layer, while increasing device complexity, ensures reliable operation by detecting negative current conditions and adjusting the reference voltage accordingly, thus improving reliability.
Solution Approach 2:
The detection circuit performs preliminary detection of negative current conditions before they can cause parasitic element malfunctions. By switching the reference voltage in advance based on detection signals, the system prevents reliability issues while maintaining a relatively simple circuit structure.
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 negative current detection circuit effectively prevents parasitic element malfunctions and reduces power consumption by ensuring the N-type semiconductor substrate and P-type well have the same voltage, thereby maintaining stable power supply and reducing heat generation during transitions.
Implementation Method 1
a comparator (CMP), configured to generate the negative current detection signal (DET) by comparing an output detection voltage (Vs) with the ground voltage (GND) or the threshold voltage
Implementation Method 2
a control circuit (62b), configured to switch between applying the ground voltage (GND) or the output voltage (OUT) to the well (P/W) in response to the negative current detection signal (DET)
Implementation Method 3
a clamp circuit (CLP), configured to operate when an absolute value of the output detection voltage (Vs) is greater than a clamp operation voltage (VCLP)
Data Source
AI summary
The present disclosure provides a semiconductor device. The semiconductor device includes: a semiconductor substrate; a well, formed in the semiconductor substrate; an output terminal, electrically connected to the semiconductor substrate; a ground terminal, configured to receive a ground voltage; a detection signal generating circuit, configured to generate a negative current detection signal when an output voltage present at the output terminal is detected to be less than the ground voltage; and a control circuit, configured to apply the ground voltage or the output voltage to the well in response to the negative current detection signal. The detection signal generating circuit includes: a comparator, configured to generate the negative current detection signal by comparing an output detection voltage with the ground voltage or the threshold voltage; a bias circuit, configured to switch between applying the output voltage or a bias voltage as the output detection voltage; and a clamp circuit.