Chen Qing – Huachuang Micro:
This week, I mainly completed the exercises from Chapter 7 and studied the knowledge related to DAC in Chapter 8. Since the author of Chapter 7 provided detailed size designs for StrongArm, the exercises in Chapter 7 focused on how the size selection of various components in the architecture affects performance.
Chapters 8-11 are all centered around DAC. In Chapter 8, the author introduced the concept and functionality of ADC. DAC can work as a standalone system or as an important component within ADC. The chapter then detailed the static and dynamic metrics. In fact, the metric definitions of DAC can be compared with those of ADC. The static metrics mainly include offset, gain error, DNL, INL, and non-monotonicity, etc.
Bu Zeng – Huawai:
This week, I completed all exercises from Chapter 7. The exercises mainly reinforced the basic concepts of the StrongArm comparator, such as OFFSET, operational processes, key node voltage changes, noise, and the impact of changing key component parameters on circuit performance.
This week, I also studied the basic concepts of DAC. The basic concepts and static characteristics of DAC include OFFSET, GAIN ERROR, differential non-linearity, and integral non-linearity concepts.
Wang Zhen – China Information Communication Technologies:：
This week, I studied Chapter 7 of the book “Analysis and Design of Data Converters” focusing on comparator design and completed all the exercises. Additionally, I began learning about the concept of DAC and its performance, which lays a theoretical foundation for the subsequent study of ADC.
He Pengjun – Shanghai University:
This week, I mainly worked on the exercises from Chapter 7, deepening my understanding of the purpose of each transistor in the StrongARM comparator, as well as the impact of the common-mode input voltage on the speed and noise of the comparator. I reviewed the noise, offset, and time constant simulations of the comparator. I also learned the basic concepts of DAC and the corresponding metrics.
Zhou Ziyang – Suzhou Kaiweite:
This week, I studied the content of Chapter 7 of ADC and completed all exercises, as well as part of the content from Chapter 8.
The content of Chapter 7 mainly discusses the design of comparators. It covers the overall design, actual waveforms, component sizes, mismatches, speed, RS locking, kickback noise, metastability, input noise, etc. It is an extension of Chapter 6.
Chapter 8 introduces DAC, which is a core component of ADC and is the main tool for determining input size. A series of improved components will follow regarding the precision of DAC.
Zheng Chao – Leuven University:
This week, I started learning the basic concepts of DAC. DAC is mainly divided into two types: one for directly obtaining analog quantities and the other for being used as a submodule in ADC. The former usually needs to maintain stable output throughout the entire cycle, while the latter only needs to maintain stable output within the time range required by ADC.
Subsequently, this chapter introduces the performance metrics of DAC, which are divided into static and dynamic types. Static non-ideal effects include offset, gain error, DNL, INL, and non-monotonicity. Offset can be understood as a vertical shift of the entire characteristic curve. Gain error is the difference between the slope of the characteristic curve and the ideal value. The first two are particularly important in DAC within ADC as they do not introduce non-linearity. DNL is defined as the difference between the actual step value and the ideal LSB, which can also introduce gain error. INL is defined as the difference between the actual output value and the ideal output value, with the maximum value of INL statistically located at the midpoint of the amplitude. INL is the sum of all previous DNL. Non-monotonicity indicates that when the input increases, the output analog value decreases. It is necessary to ensure that DNL is less than 1dB to avoid this.