Fuse Memory Power Supply Voltage Switching for Data Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuse memory circuits in semiconductor integrated circuits are prone to failures such as gate oxide film breakdown and diffusion junction breakdown, which can lead to unintended cutting of fuse elements, resulting in data loss during transistor failures.
Innovation Solution
A power supply circuit that switches between two voltage levels, allowing for cutting of fuse elements during programming and preventing cutting during normal operation by maintaining a lower voltage level, thereby enhancing the reliability of the fuse memory circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high power supply voltage is applied to the fuse memory circuit during normal operation, then the fuse element can be cut for programming, but the transistor may fail due to gate oxide film breakdown or diffusion junction breakdown, causing unintended cutting of the fuse element
Solution Approach 1:
The power supply voltage to the fuse memory circuit is made dynamic rather than static. The voltage level changes based on the operational state: a first voltage level (capable of cutting the fuse element) is supplied during programming mode, while a second voltage level (lower than the first, incapable of cutting the fuse element) is supplied during normal operation mode. This dynamic voltage adjustment allows the system to achieve fuse cutting when needed while preventing unintended cutting during normal operation, thereby resolving the contradiction between programming capability and operational reliability.
Solution Approach 2:
The voltage parameter of the power supply to the fuse memory circuit is changed according to different operational requirements. By switching between two distinct voltage levels (first voltage level for programming, second lower voltage level for normal operation), the system can control whether the fuse element can be cut. This parameter change approach enables the system to maintain high reliability during normal operation while still allowing fuse cutting during programming, thus resolving the technical contradiction.
2Reliability
If a low power supply voltage is applied to the fuse memory circuit during normal operation, then transistor failures cannot cause unintended fuse cutting, but the fuse element cannot be cut when programming is needed
Solution Approach 1:
The power supply system dynamically adjusts the voltage level based on the required function. During normal operation, a second voltage level (lower, incapable of cutting the fuse element) is supplied to protect against unintended cutting. During programming mode, the system switches to a first voltage level (higher, capable of cutting the fuse element) to enable programming. This dynamic voltage switching resolves the contradiction by providing the appropriate voltage level for each operational context.
Solution Approach 2:
The power supply voltage to the fuse memory circuit is periodically or conditionally switched between two states: a programming state with a first voltage level that can cut the fuse element, and a normal operation state with a second lower voltage level that cannot cut the fuse element. This periodic or conditional voltage switching enables the system to alternate between programming capability and operational protection, resolving the contradiction between these two requirements.
3Device complexity
If the power supply voltage level is not switched, then the circuit structure is simpler, but the fuse memory circuit cannot distinguish between programming mode and normal operation mode
Solution Approach 1:
The power supply circuit is designed to dynamically switch between two voltage levels based on operational mode. The circuit includes voltage switching mechanisms that respond to control signals indicating whether the system is in programming mode or normal operation mode. This dynamic voltage switching capability, while adding some circuit complexity, enables the fuse memory circuit to properly distinguish between programming and normal operation modes, thus resolving the contradiction between simplicity and functionality.
Data Source
AI summary
A semiconductor integrated circuit includes: a power supply pin configured to receive an external power supply voltage; a fuse memory circuit including a fuse element; and a power supply circuit, whose output is connected to the fuse memory circuit, configured to receive the external power supply voltage, the power supply circuit being switchable in response to a control signal between (i) a first state in which an internal power supply voltage of a first voltage level, which is capable of cutting the fuse element, is supplied to a power supply line of the fuse memory circuit and (ii) a second state in which the internal power supply voltage of a second voltage level lower than the first voltage level, which is incapable of cutting the fuse element, is supplied to the power supply line of the fuse memory circuit.