Dual-Power Reset Circuit Without Large Cutoff Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices that reset an operation state require large transistors to cut off power supply lines, leading to increased device size and power consumption.
Innovation Solution
An electronic device configuration that includes a regulator, a first circuit unit for generating operation signals, a second circuit unit for processing, and a signal transmitting unit to block current flow, eliminating the need for a dedicated transistor to cut off power supply lines and reducing device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a switch of a transistor is used to cut off the power supply line directly, then the operation state can be reset accurately, but the device size becomes large due to the requirement of a large size transistor with small on-resistance
Solution Approach 1:
The power supply system is segmented into two independent paths: a first power supply line providing a first power supply voltage, and a second power supply line providing a second power supply voltage to the processing unit. This segmentation allows the reset function to operate on the second power supply line without requiring a large transistor to handle high current, thus reducing device size while maintaining reset accuracy.
Solution Approach 2:
A signal transmitting unit is introduced as an intermediary component between the first circuit unit and the second circuit unit. This unit blocks the transmission of signals from the first circuit unit to the second circuit unit when reset is required, providing an indirect method to control the processing unit without directly cutting off the main power supply line with a large transistor.
2Reliability
If a large size transistor is added to cut off the power supply line, then the reset function works reliably, but the device complexity increases
Solution Approach 1:
The power supply system is divided into two independent power supply lines with separate voltage levels. The first power supply line operates independently from the second power supply line, allowing the reset function to control the second power supply voltage without requiring a large transistor on the main power path, thereby simplifying the overall circuit structure.
Solution Approach 2:
The first power supply voltage serves multiple functions: it powers the operation signal generating unit and the reset unit, and also enables the signal transmitting unit to block signal transmission. This multi-functionality reduces the need for additional dedicated components, simplifying the circuit structure while maintaining reliable reset functionality.
3Reliability
If the power supply line is cut off directly by a transistor, then the operation state can be reset, but power consumption increases due to the transistor's on-resistance
Solution Approach 1:
The power supply is segmented into two lines with different voltage levels. The reset unit controls the second power supply voltage (lower voltage) rather than the first power supply voltage (higher voltage). Since power loss is proportional to the square of the voltage (P=V²/R), operating the reset function at a lower voltage significantly reduces power consumption while maintaining the ability to reset the operation state.
Solution Approach 2:
The signal transmitting unit acts as an intermediary that blocks signal transmission from the first circuit unit to the second circuit unit during reset operations. This indirect control mechanism eliminates the need for a large transistor with high on-resistance in the main power path, thereby reducing power loss while achieving the reset function.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An operation signal generating unit 11 and a reset unit 12 are included in a first circuit unit 10 that operates based on a first power supply voltage V1 and an output operation of a second power supply voltage B2 is stopped by outputting a reset signal Sr from the reset unit 12 to a regulator 20 in accordance with an operation signal Si of the operation signal generating unit 11. Hence, unlike a conventional technique, a large transistor for cutting off a power supply line is unnecessary, and therefore a device size can be reduced.