Static and Dynamic CMOS are the two types of CMOS. The static CMOS is a combinational circuit. It made up with pull-up network and pull-down network functions. On the other side, the dynamic CMOS is a digital logic that has a single clock signal to execute the pre charge and evaluation operation.
In this article, we are going to discuss the Difference Between static and dynamic CMOS in detail.
What is CMOS?
CMOS is a technology that is used to develop the different integrated circuits. It can be used as complementary and symmetrical pairs of p-type and n-type MOSFETs to simulate the various functions. CMOS technology is widely used to the design different digital logic circuits. There are two types of CMOS as mentioned below.
Static CMOS
The static CMOS is a combinational circuit with pull-up network (PUN) and pull-down network (PDN). Static CMOS is particularly used for designing the high level integrated circuits. The static CMOS consumes low power and gives reliable performance in a system.
Characteristics of Static CMOS
Here are the major characteristics of Static CMOS as mentioned below.
- The static CMOS consumes power during the time of switching. Except this, the static CMOS does not consume any power. There is no direct path for ground in the static CMOS.
- There are two types of transistors present in the static CMOS to minimize the current leakage.
- Static CMOS has a defined high noise margin that makes the whole circuit diverse.
- The design of the static CMOS has a higher transistor density and its balanced design increases the performance and consistency.
Advantages of CMOS
- Static CMOS circuits consume power only during state transitions and not during steady state.
- Static CMOS gates have a high noise margin, making them less susceptible to noise and variations in supply voltage.
- The stable state of static CMOS circuits ensures consistent performance and reliability.
- Static CMOS logic is straightforward to design and understand, as it uses well-defined logic levels.
Disadvantages of CMOS
- Static CMOS circuits can take up more silicon area compared to dynamic circuits due to the need for multiple transistors per gate.
- Static CMOS circuits may have slower switching speeds compared to dynamic CMOS circuits because of the need for more complex transistors.
Applications of CMOS
- Digital logic circuits
- Microprocessors
- Memory chips (e.g., SRAM)
- Low-power and battery-operated devices
Block Diagram of Static CMOS
Here is the block diagram of the static CMOS as mentioned below.
 Static CMOS
Dynamic CMOS
Dynamic CMOS is a digital circuit. It has a single clock signal. It helps the system to execute the pre charge operation. The capacitors of the dynamic CMOS have ability to generate high-intensity performance with low power consumption. The dynamic CMOS relay on continuous electricity to maintain all functions.
Characteristics of Dynamic CMOS
Here are the major characteristics of Dynamic CMOS as mentioned below.
- Dynamic CMOS can perform faster switching. These circuits are designed to develop high-intensity systems where increase capacity and higher speed are needed.
- The dynamic CMOS consumes power during the switching time. The circuit does not need continuous power to maintain the logic state.
- Dynamic CMOS have the capacitors to save the charge and the logic state can be determined by the capacitors only.
- This type of CMOS needs a CLK signal to refresh the stored charge in a certain time to get an accurate result.
- The stored change may leak as the circuits of the dynamic CMOS are more sensitive to knowledge and other factors.
Advantages of Dynamic CMOS
- Dynamic CMOS circuits can achieve higher speeds compared to static CMOS due to the reduced number of transistors.
- Dynamic CMOS circuits often require less area on the silicon chip, allowing for higher density and more compact designs.
- Dynamic CMOS can be more power-efficient in high-speed applications, particularly when the circuit operates at high frequencies.
Disadvantages of Dynamic CMOS
- Dynamic CMOS circuits can consume more power during the switching phase.
- Dynamic circuits can be more complex to design.
- It requires precise timing and careful management of charge storage.
- Dynamic CMOS circuits are more susceptible to noise, which can lead to data corruption.
Applications of Dynamic CMOS
- High-speed processors
- DRAM (Dynamic Random-Access Memory)
- High-density logic circuits
- Advanced digital systems requiring fast processing
Block Diagram Of Dynamic CMOS
Here is the bloc diagram of the dynamic CMOS as mentioned below.
 Dynamic CMOS
Difference Between Static and Dynamic CMOS
Feature |
Static CMOS |
Dynamic CMOS |
Power Consumption |
Low static power consumption. |
Lower average power consumption. |
Speed |
Moderate speed. |
High speed. |
Complexity |
More transistors per gate. |
More complex design with timing and charge management. |
Transistor Count |
Higher. |
Lower. |
Noise Immunity |
High noise immunity due to stable logic levels. |
Lower noise immunity. |
Charge Storage |
Does not rely on charge storage. |
Relies on capacitor charge storage. |
Clock Dependency |
Not clock-dependent. |
Clock-dependent. |
Power Dissipation |
Static power dissipation is minimal. |
Primarily dynamic power dissipation. |
Leakage Current |
Very low leakage current. |
Higher leakage current due to charge storage in capacitors. |
Design Complexity |
Easier to design and implement. |
More complex design with timing and refresh requirements. |
Use in Memory |
Used in SRAM. |
Used in DRAM. |
Applications |
General-purpose logic gates, microprocessors, microcontrollers, digital logic circuits making. |
High-speed logic circuits, high-performance processors, DRAM, pipelined architecture making. |
Refresh Requirement |
No refresh required. |
Requires periodic refresh. |
Power Supply Variation |
Tolerant to power supply variations. |
Less tolerant to power supply variations. |
Conclusion
The static CMOS is a combinational circuit with pull-up network (PUN) and pull-down network (PDN). Static CMOS is particularly used for designing the high level integrated circuits. The static CMOS consumes low power and gives reliable performance in a system. Dynamic CMOS is a digital circuit. It has a single clock signal. It helps the system to execute the pre charge and evaluation operation. The capacitors of the dynamic CMOS have ability to generate high-intensity performance with low power consumption. The dynamic CMOS relay on continuous electricity to maintain all functions. The static CMOS consumes power during the time of switching. Except this, the static CMOS does not consume any power. There is no direct path for ground in the static CMOS. Dynamic CMOS can perform faster switching.
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Frequently Asked Questions on Difference Between Static CMOS and Dynamic CMOS-FAQ’S
What is Static CMOS?
The static CMOS is a combinational circuit with pull-up network (PUN) and pull-down network (PDN). Static CMOS is particularly used for designing the high level integrated circuits. The static CMOS consumes low power and gives reliable performance in a system.
What is The Main Difference Between static and dynamic CMOS?
The static CMOS consumes power during the time of switching. Except this, the static CMOS does not consume any power. There is no direct path for ground in the static CMOS. Dynamic CMOS can perform faster switching.
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