Charge-Pump Voltage Level Shifter Against Low-Voltage Fighting
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Solution Overview
Problem
Conventional voltage level shifters struggle with voltage fighting and power consumption issues in low supply voltage applications, leading to reduced signal transition speed and inefficiency.
Innovation Solution
A voltage level shifter incorporating a boost circuit and cross-coupled transistors that perform pre-charging and charge pump operations to increase input terminal voltages, reducing voltage fighting and protecting differential transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional voltage level shifter is used in low supply voltage applications, then the device can operate at low voltage, but voltage fighting occurs on the output terminal causing reduced signal transition speed
Solution Approach 1:
The boost circuit performs pre-charging operations on the input terminals of the cross-coupled transistors before the voltage level shifting operation. This preliminary action ensures that the input terminals are already charged to appropriate voltage levels, preventing voltage fighting during the switching operation and maintaining fast signal transition speed while enabling operation at low supply voltages
2Speed
If a conventional voltage level shifter is used in low supply voltage applications, then the device can operate at low voltage, but power consumption increases due to voltage fighting
Solution Approach 1:
The boost circuit performs pre-charging operations on the input terminals before the voltage level shifting operation, ensuring that transistors are already in appropriate states. This prevents voltage fighting during switching, which would otherwise cause excessive power consumption, while maintaining fast signal transition speed
Solution Approach 2:
The boost circuit converts the low supply voltage condition (which causes voltage fighting) into a benefit by actively managing the voltage levels on input terminals. The charge pump generates boosted voltage pulses that compensate for the low supply voltage, turning the harmful voltage fighting effect into a controlled operation that actually improves efficiency
3Device complexity
If the voltage level shifter operates without protection in low supply voltage applications, then the circuit remains simple, but differential transistors are damaged by high supply voltage
Solution Approach 1:
The boost circuit acts as an intermediary between the low supply voltage and the differential transistors. It generates boosted voltage pulses that protect the differential transistors from high supply voltage damage while allowing the voltage level shifter to operate correctly. This intermediary function adds necessary protection without making the circuit overly complex
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances signal transition speed and protects transistors from high supply voltage damage, enabling efficient operation in energy-saving applications.
Implementation Method 1
generate at least one voltage pulse based on a charge pump operation according to at least one control pulse signal
Implementation Method 2
The pair of differential transistors is coupled to the pair of cross-coupled transistors and receives a pair of input signals
Data Source
AI summary
A voltage level shifter is provided. The voltage level shifter includes a voltage level shift circuit and a boost circuit. The voltage level shift circuit operates between a first voltage and a second voltage. The voltage level shift circuit includes a pair of cross-coupled transistors and a pair of differential transistors. The pair of differential transistors is coupled to the pair of cross-coupled transistors and receives a pair of input signals. The boost circuit is coupled to the voltage level shift circuit. The boost circuit executes a pre-charging operation on boost input terminals of the pair of cross-coupled transistors, generates a voltage pulse based on a charge pump operation according to a control pulse signal, and provides the voltage pulse to the boost input terminals. The control pulse signal is generated corresponding to a transient edge of the pair of input signals.