Level Shift Circuit Using Complementary Pulses for Zero Static Power
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Solution Overview
Problem
Traditional level shift circuits have high static power consumption and low signal transmission speed, which affects the performance of electronic devices such as fingerprint identification devices.
Innovation Solution
A level shift circuit design where the first and second high voltage transistors are not in an ON state simultaneously, eliminating turn-on current and incorporating a complementary signal generating unit, sub-latch unit, and load matching unit to achieve high-speed signal transmission without static power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If a traditional level shift circuit is used to shift voltage levels between digital and analog circuits, then level shifting function is achieved, but static power consumption is high
Solution Approach 1:
The circuit dynamically controls the switching states of transistors based on signal conditions. The first and second high voltage transistors are controlled to never be in ON state simultaneously through the complementary signal generating unit, creating a dynamic switching mechanism that eliminates static power consumption while maintaining level shifting capability.
Solution Approach 2:
The circuit changes the voltage level parameter of the signal from low voltage domain to high voltage domain. By using complementary signaling and controlled transistor switching, the circuit transforms the signal voltage level without creating continuous current paths, thereby reducing power consumption while achieving the required voltage level transformation.
2Speed
If a traditional level shift circuit is used to shift voltage levels, then level shifting function is achieved, but signal transmission speed is low
Solution Approach 1:
The complementary signal generating unit generates complementary signals in advance to control the high voltage transistors. This preliminary preparation of control signals ensures that the transistors are switched optimally, enabling fast signal transmission while maintaining proper level shifting function.
Solution Approach 2:
The circuit employs dynamic switching of high voltage transistors controlled by complementary signals, allowing the circuit to respond quickly to input changes. This dynamic operation enables high-speed signal transmission while maintaining reliable level shifting between voltage domains.
3Productivity
If the first transistor and first high voltage transistor are both in ON state, then signal transmission path is established, but turn-on current is generated causing static power consumption
Solution Approach 1:
The circuit creates an asymmetric control relationship where the first high voltage transistor is controlled by a complementary signal that is logically opposite to the control signal of the first transistor. This asymmetric control ensures that when one transistor is ON, the other is OFF, eliminating simultaneous conduction and the associated turn-on current that would cause static power consumption.
Solution Approach 2:
The circuit converts the potential harm of simultaneous transistor conduction (turn-on current) into a benefit by using complementary signaling. The complementary control mechanism, which could have been seen as adding complexity, actually eliminates the harmful current path while maintaining signal transmission capability, turning a potential problem into a solution.
Data Source
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AI summary
Some embodiments of the application provide a level shift circuit and a fingerprint identification device. The level shift circuit comprises a complementary signal generating unit, a high voltage pulse generating unit and a shift and latch unit; the high voltage pulse generating unit is connected to the complementary signal generating unit and the shift and latch unit; the complementary signal generating unit is used to receive a target signal at a low voltage domain and output a complementary signal of the target signal and the target signal; the high voltage pulse generating unit is used to generate a high voltage pulse according to the target signal and complementary signal; the shift and latch unit is used to shift the target signal from the low voltage domain to a high voltage domain when a high voltage pulse is generated, and is used to latch and output the target signal at the high voltage domain. By applying the embodiments of this application, a circuit may transmit a target signal at a high speed without any static power consumption.