Clock Switch Circuit With Tri-State Buffer for Stable Frequency Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices experience reliability issues due to clock signal frequencies exceeding allowable ranges during stabilization times, leading to hot carrier injection and decreased operational reliability.
Innovation Solution
A clock switch device with a control circuit that deactivates the output enable signal when the clock signal frequency varies and activates it when the frequency stabilizes, using a tri-state buffer to maintain a high impedance state until the signal is buffered and output as a constant-frequency clock signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the clock signal is output during stabilization time, then the system can operate continuously, but the clock signal frequency exceeds the allowable range causing reliability issues
Solution Approach 1:
The control circuit performs preliminary detection of clock signal frequency stability before enabling the output enable signal. By detecting whether the frequency has stabilized within the allowable range in advance, the system prevents outputting unstable clock signals that would cause reliability issues, while still maintaining continuous operation capability.
Solution Approach 2:
The control circuit continuously monitors the clock signal frequency and provides feedback control over the output enable signal. When the frequency exceeds the allowable range, the control circuit deactivates the output enable signal; when the frequency stabilizes within the range, it activates the signal. This feedback mechanism ensures reliable operation while maintaining continuous system functionality.
2Duration of action of stationary object
If the output enable signal is always activated, then the clock signal can be continuously output, but hot carrier injection occurs during frequency transitions
Solution Approach 1:
The control circuit applies preliminary anti-action by deactivating the output enable signal during frequency transitions before hot carrier injection can occur. By detecting frequency instability in advance and preventing output during these transitions, the system eliminates the harmful hot carrier injection effect while maintaining continuous operational capability through rapid reactivation once stability is achieved.
3Adaptability or versatility
If the clock signal frequency is allowed to vary during stabilization, then the system can adapt to different conditions, but the frequency exceeds the allowable range
Solution Approach 1:
The system dynamically adjusts the output enable signal state based on real-time frequency stability detection. During stabilization, the system allows frequency variation (high adaptability) while keeping the output disabled. Once the frequency stabilizes within the allowable range, the output is enabled (high precision). This dynamic switching resolves the contradiction between adaptability and precision.
Data Source
AI summary
A clock switch device includes a control circuit and a tri-state buffer. The control circuit deactivates an output enable signal when a frequency of a clock signal varies and activates the output enable signal when the frequency of the clock signal is maintained without change. The tri-state buffer maintains an output electrode at a high impedance state when the output enable signal is deactivated and buffers the clock signal and outputs the buffered clock signal through the output electrode as an output clock signal when the output enable signal is activated.