Clock Signal Generator Using CTAT/PTAT Current Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor memory devices face challenges in maintaining consistent clock signal cycles due to variations in temperature, which affect the operation characteristics of memory cells.
Innovation Solution
A clock signal generator that compensates for temperature changes by generating a reference current using a combination of CTAT and PTAT currents, which are then used to alternately discharge and charge capacitors to produce clock signals with linear temperature characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature compensation is implemented using conventional circuits, then clock cycle stability is improved, but device complexity increases
Solution Approach 1:
The patent combines PTAT and CTAT current generation circuits into a unified reference current generation system. The PTAT current circuit and CTAT current circuit are integrated to work together, with their currents summed to produce a reference current that compensates for temperature effects. This merging approach achieves temperature compensation functionality while managing circuit complexity through systematic integration of complementary current sources.
2Reliability
If temperature compensation circuits are added to maintain clock stability, then operational reliability is improved, but power consumption increases
Solution Approach 1:
The patent utilizes parameter changes in transistor operating conditions to generate temperature-dependent currents. By adjusting the biasing conditions and operating parameters of transistors in the PTAT and CTAT circuits, the system generates currents that naturally compensate for temperature effects without requiring additional active power compensation mechanisms. This approach leverages inherent semiconductor parameter variations to achieve temperature compensation.
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 generator ensures the clock signal cycle remains consistent across varying temperatures, reducing power consumption and maintaining operational stability in memory devices.
Implementation Method 1
receiving a bandgap reference voltage from a bandgap reference circuit
Implementation Method 2
generating a first CTAT current by adding the first current to the second current
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A method of generating clock signals includes: receiving a bandgap reference voltage from a bandgap reference circuit; generating a first current having a first curvature characteristic based on the bandgap reference voltage; generating a second current having a second curvature characteristic based on the bandgap reference voltage; generating a first complementary to absolute temperature (CTAT) current by adding the first current to the second current; receiving a temperature-variable voltage and a temperature-fixed voltage from a voltage generator; generating an offset current based on the temperature-variable voltage and the temperature-fixed voltage; generating a reference current by adding the first CTAT current to the offset current; and generating the clock signals by alternately discharging a first capacitor and a second capacitor based on the reference current, and charging the first capacitor and the second capacitor based on a power voltage.