Master Latch Flip-Flop Layout for Low-Voltage Hold Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flip-flops face performance issues at low voltages and clock frequencies due to high power consumption, transistor count, and hold time constraints, leading to unreliable operation and increased power consumption.
Innovation Solution
A master latch and flip-flop design with a reduced number of clock-connected transistors and optimized hold time, using a single-phase clock and a specific logic circuit configuration to minimize stack height and transistor count, thereby reducing power consumption and hold time violations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If transmission gate flip-flops are used to achieve widespread adoption in sequential logic designs, then the design is widely compatible, but power consumption increases and performance degrades at low voltages
Solution Approach 1:
The patent extracts the clock signal connection from multiple transistors and concentrates it to only two transistors (M1 and M3) in the master latch. This extraction reduces the number of transistors affected by clock switching activity, thereby reducing dynamic power consumption while maintaining the flip-flop's functionality in sequential logic designs.
Solution Approach 2:
The patent changes the operational parameters by using a single-phase clock signal instead of multi-phase clocks, and optimizes the transistor sizing and configuration to operate reliably at low voltages. The master latch is designed to function correctly with voltage levels suitable for low-power applications, improving performance at low voltages while maintaining compatibility.
2Reliability
If more transistors are connected to the clock signal to improve functionality, then the design becomes more robust, but power consumption increases
Solution Approach 1:
The patent extracts and removes unnecessary clock-connected transistors from the design. By carefully analyzing the functionality required, it determines that only two transistors (M1 and M3) need to be connected to the clock signal, eliminating redundant clock connections that would increase power consumption without adding functional value.
Solution Approach 2:
Instead of connecting more transistors to the clock signal to improve robustness (the conventional approach), the patent inverts the approach by minimizing clock-connected transistors and achieving robustness through optimized logic design and transistor configuration, demonstrating that fewer clock connections can provide equal or better reliability.
3Device complexity
If the stack height is increased to reduce transistor count, then device count decreases, but performance degrades at low voltages
Solution Approach 1:
The patent applies local quality by optimizing the transistor configuration in critical paths. Instead of uniformly reducing stack height throughout the circuit, it carefully designs the master latch with specific transistor arrangements (using only two clock-connected transistors) that maintain low stack height in voltage-critical paths while allowing higher stacks in non-critical areas, thus maintaining low voltage performance with reduced overall transistor count.
4Device complexity
If dynamic operation is used to reduce transistor count, then device count decreases, but reliability decreases at low voltages
Solution Approach 1:
The patent inverts the conventional approach by using a fully static logic design instead of dynamic operation. The master latch uses static CMOS logic with carefully selected transistor configurations that maintain stable operation at low voltages without requiring dynamic charging/discharging mechanisms, achieving both low transistor count and high reliability.
5Loss of time
If clock buffering is added to improve transition time, then timing performance improves, but device count increases
Solution Approach 1:
The patent extracts the clock buffering function from separate dedicated buffer circuits and integrates it directly into the master latch structure through the clock-connected transistors M1 and M3. This integration provides necessary clock signal conditioning and transition control without requiring additional standalone buffer circuits, thus improving timing performance without increasing overall device count.
Data Source
AI summary
There is provided a master latch configured to receive a clock signal and comprising: a plurality of transistors, wherein more than one and fewer than four transistors of the plurality of transistors are configured to receive the clock signal. Additionally there is provided a master latch configured to receive a clock signal and comprising: a plurality of transistors, wherein fewer than four transistors of the plurality of transistors are configured to receive the clock signal; and wherein a maximum number of transistors connected in series between a voltage rail adapted for connection to a power supply and an output of the master latch is less than three. Flip-flops comprising the master latches are also described.