Current-Mirror Level Shifters for Wide Voltage Delta
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional level shifters in integrated circuits face limitations in operating voltage range due to 'fighting' between n-type and p-type transistors, which restricts the maximum voltage delta and power saving capabilities.
Innovation Solution
The implementation of a non-fighting level shifter circuit using current mirrors to control the state of transistors, ensuring n-type transistors operate without competition, thereby eliminating the voltage range limitations and allowing for an unlimited voltage delta between VDDA and VDDP.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional level shifters use fighting between n-type and p-type transistors to control voltage levels, then the circuit can achieve voltage level shifting, but the operating voltage range is limited due to transistor competition
Solution Approach 1:
The patent introduces current mirrors as intermediary components that mediate between the input signal and the n-type transistors. The current mirrors convert voltage signals to current signals and back, eliminating the need for direct voltage competition between n-type and p-type transistors. This intermediary mechanism allows the level shifter to operate across unlimited voltage ranges while maintaining controlled transistor states through current rather than direct voltage fighting.
2Use of energy by moving object
If the voltage delta between VDDA and VDDP is increased to expand operating range, then power saving capabilities improve, but conventional level shifters cannot maintain proper transistor operation
Solution Approach 1:
The patent changes the control parameter from voltage to current. By using current mirrors to control the n-type transistors through current signals rather than direct voltage control, the circuit can maintain reliable transistor operation even when the voltage delta between VDDA and VDDP is maximized. This parameter transformation allows independent optimization of power saving (through large voltage delta) and transistor reliability (through current-based control).
3Adaptability or versatility
If conventional level shifters are designed to support larger voltage deltas, then the operating range expands, but the circuit area and speed are significantly impacted
Solution Approach 1:
The current mirror circuits serve multiple functions simultaneously: they control the n-type transistors, provide voltage level shifting, enable unlimited operating ranges, and maintain compact circuit area. This multi-functionality allows the level shifter to achieve expanded voltage delta support without proportionally increasing circuit area, as the same current mirror structures perform both control and signal transformation tasks.
Data Source
AI summary
A level shifter circuit includes a first current mirror coupled between a power terminal and a ground terminal, a second current mirror coupled between the power terminal and the ground terminal, and a level shifter. The level shifter includes a first transistor coupled to the first current mirror and a second transistor coupled to the second current mirror. The first current mirror and the second current mirror control a state of the first transistor and the second transistor.