Voltage Power Switch With Level Shifting for Safe Fuse Programming
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Solution Overview
Problem
Semiconductor devices at advanced process nodes, such as 5 nm, can only operate at low voltages, making it challenging to provide the higher voltages required for fuse programming without damaging other components, as existing voltage switches may exceed safe limits when providing high voltages for extended durations.
Innovation Solution
A voltage power switch with a lock circuit and voltage level shifter configuration that selectively outputs a high voltage for fuse programming and a safe intermediate voltage for non-fuse programming, using a cascaded latch structure and digital logic gates to ensure safe operation within terminal voltage limits, employing NMOS and PMOS transistors biased by the voltage level shifter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a voltage power switch provides high voltage for fuse programming, then fuse programming capability is enabled, but other components may be damaged due to exceeding their voltage tolerance
Solution Approach 1:
The voltage power switch dynamically changes its output voltage based on operational mode. During fuse programming, it outputs high voltage (e.g., 1.8V) to blow the fuse link. During normal operation, it outputs a safe intermediate voltage (e.g., 1.2V) that is compatible with standard CMOS components. This dynamic voltage switching is controlled by mode selection logic that responds to control signals indicating the desired operational state.
Solution Approach 2:
The invention changes the voltage parameter output by the power switch depending on the operational context. The switch circuit includes transistors and logic gates that respond to control signals to select between different voltage output levels. The voltage level is adjusted from a high level suitable for fuse programming to a lower intermediate level suitable for normal circuit operation, thereby preventing component damage while enabling fuse programming capability.
2Power
If a voltage power switch provides high voltage for extended durations, then power delivery capability is improved, but semiconductor devices are damaged due to exceeding voltage limits
Solution Approach 1:
The voltage power switch operates in periodic cycles, alternating between fuse programming mode and normal operation mode. During fuse programming, high voltage is applied for a brief period to blow the fuse link. After programming is complete, the switch transitions to normal operation mode where the intermediate voltage is maintained for extended durations to power the circuit safely. This periodic switching between voltage levels ensures that high voltage is applied only when necessary and for short durations, preventing cumulative damage to voltage-sensitive components.
Solution Approach 2:
The power switch dynamically adjusts its output voltage level based on the operational phase. The switch circuit includes control logic that monitors the operational state and automatically transitions between high voltage and intermediate voltage outputs. This dynamic control ensures that high voltage is delivered only during the brief fuse programming window, while the circuit operates at safe voltage levels during normal function, thereby maintaining both power delivery capability and device reliability.
3Device complexity
If a voltage power switch uses simple switching logic, then device complexity is reduced, but voltage control precision is insufficient to prevent exceeding terminal voltage limits
Solution Approach 1:
The invention introduces an intermediate voltage level (e.g., 1.2V) that serves as a mediator between the high voltage used for fuse programming and the low voltage used for normal operation. This intermediate voltage is generated by a dedicated voltage generation circuit that includes transistors and logic gates configured to output this specific intermediate level. The intermediate voltage acts as a safe operating point that prevents exceeding terminal voltage limits while still enabling proper circuit function, thereby achieving precise voltage control without requiring overly complex switching logic.
Solution Approach 2:
The voltage output is segmented into distinct levels: a high voltage level for fuse programming, an intermediate voltage level for normal operation, and a low voltage level for standby or shutdown. The switching logic is segmented into corresponding control paths that selectively activate each voltage level based on operational mode. This segmentation allows for precise control of voltage transitions and ensures that the circuit operates within safe voltage limits during normal operation while still enabling high voltage output when needed for fuse programming.
Data Source
AI summary
A voltage power switch includes circuitry configured to output a known voltage. The voltage power switch includes a lock circuit configured to output a known state and a voltage level shifter configured to receive an input, the input being based on the known state output by the lock circuit. The voltage power switch, using an output circuit, is configured to output a known voltage level based on an output of the voltage level shifter, wherein the known voltage is one of a high voltage VHI for a fuse programing period or a first non-zero intermediate voltage VMID1 for a non-fuse programming period.