Voltage Level Shifter With Low-Threshold Leakage Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing voltage level shifters face challenges in achieving high-speed operation while preventing power leakage when interfacing between low and high voltage integrated circuits, particularly due to the higher threshold voltage of transistors leading to longer state-switching times and potential power leakage pathways.
Innovation Solution
A voltage level shifter design incorporating a first transistor, a second transistor, a third transistor, and a fourth transistor with a low threshold voltage, along with an inverter, where the gate of the fourth transistor is connected to the external input signal, ensuring the gate-source voltage drop is negative, thereby preventing power leakage and enabling high-speed operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transistor with higher threshold voltage is used in the voltage level shifter, then the transistor can be turned off more reliably, but the state-switching time increases and high-speed operation cannot be achieved
Solution Approach 1:
The patent changes the threshold voltage parameter of the fourth transistor from high to low, enabling fast switching. The low threshold voltage allows the transistor to switch states rapidly while the gate-source voltage control mechanism ensures reliable off-state when needed.
2Speed
If a transistor with lower threshold voltage is used to achieve high-speed operation, then the state-switching time decreases, but power leakage occurs due to incomplete turn-off
Solution Approach 1:
The patent uses feedback control through the gate-source voltage mechanism. The gate voltage is controlled based on the required operation state, providing feedback control that ensures the low threshold voltage transistor is completely turned off when needed, preventing power leakage while maintaining fast switching capability.
Solution Approach 2:
The patent changes the threshold voltage parameter to low, enabling fast switching, and compensates for potential power leakage through controlled gate-source voltage that ensures complete turn-off when required.
3Power
If the gate-source voltage drop is positive, then the transistor can conduct current, but power leakage occurs in the off-state
Solution Approach 1:
The patent ensures the gate-source voltage drop is negative, which completely turns off the low threshold voltage transistor and prevents power leakage. When current conduction is needed, the voltage control mechanism adjusts to allow proper conduction without leakage.
Data Source
AI summary
The present invention discloses a voltage level shifter capable of interfacing between two circuit systems having different operating voltage swings. The voltage level shifter comprises an input buffer having a low supply voltage for inverting an external input signal to an internal input signal, and an output buffer having a high supply voltage for inverting the internal input signal to an external output signal. The high level of the external input signal is lower than the high level of the external output signal. The voltage level shifter is designed such that the input buffer is operating to achieve a low-leakage and high-speed performance.