Voltage Diagnostic Circuit Serial Pin Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power supply monitoring systems require a separate diagnostic input pin to read status signals, which can be inconvenient and limited in pin availability, especially in safety-related systems where a two-channel hardware structure may be necessary.
Innovation Solution
A microcontroller-based circuit that reads status signals from a diagnostic circuit via a serial input connected to a shift register's serial output, eliminating the need for a separate diagnostic input pin and allowing continuous monitoring without a clock signal, using sensors to detect undervoltage or overvoltage conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate diagnostic input pin is used to read status signals from a diagnostic circuit, then the microcontroller can monitor power supply status, but the pin availability is limited and device complexity increases
Solution Approach 1:
The patent combines the diagnostic function with the existing serial communication interface by integrating the diagnostic circuit's output into the shift register's data input. This merging eliminates the need for a separate diagnostic input pin on the microcontroller, as the status signals are now transmitted through the existing serial communication pathway that uses pins already allocated for data transmission.
Solution Approach 2:
The shift register is designed to serve multiple functions: it handles both regular data transmission and diagnostic status signal transmission through its data input. By making the shift register universal, the system can monitor power supply status without requiring dedicated pins solely for diagnostics, thus improving pin utilization efficiency.
2Loss of information
If a separate diagnostic input pin is used, then status signals can be read, but the system requires additional hardware connections and clock signals
Solution Approach 1:
The diagnostic status signals are merged into the existing serial communication data stream. The shift register's data input receives both regular data and diagnostic status signals, which are then transmitted through the same serial output connection to the microcontroller, eliminating the need for separate hardware connections and clock signals for diagnostics.
Solution Approach 2:
The serial communication interface is designed to handle multiple types of data transmission simultaneously. The shift register can load data from either the parallel interface or the diagnostic circuit's data input, and transmit everything through the same serial output, making the communication pathway universal and eliminating redundant hardware.
3Use of energy by moving object
If continuous monitoring is implemented without clock signal, then power consumption is reduced and data availability is improved, but reliability during power fluctuations may be compromised
Solution Approach 1:
The shift register is configured to apply the diagnostic bit value to the microcontroller's input in advance, before a clock signal would normally be required. This preliminary action ensures that the status information is already available at the microcontroller input, allowing the system to enter a low-power state without compromising the ability to detect power supply issues.
Solution Approach 2:
The diagnostic circuit and shift register are designed to automatically maintain the diagnostic bit value at the microcontroller input without requiring active clocking or power consumption from the microcontroller. The circuit self-maintains the signal level, allowing the microcontroller to monitor power supply status passively and enter low-power modes when appropriate.
Data Source
Figure 1~2a
Figure 2b~2c
Figure 3
AI summary
The invention relates to a circuit (10) for monitoring an output voltage of a voltage supply (12). The circuit (10) comprises a microcontroller (14) for controlling a system, a shift register (16a, 16b, 16c) and a diagnostic circuit (22). The microcontroller (14) comprises an input (MISO) for receiving serial output data (Q7) of the shift register (16a, 16b, 16c), wherein the input (MISO) is connected to the serial output (Q7) of the shift register (16a, 16b, 16c). The diagnostic circuit (22) is formed for diagnosing the voltage supply (12) and has a diagnostic output (status signal) which is connected to a data input (D7) of the shift register (16a, 16b, 16c) for inputting a diagnostic bit.