Due to the high speed of the IC and the LSI semiconductor itself, and in order to achieve the purpose of normal operation of the High Density Printed Circuit Board Design, the technical competition is becoming more and more fierce and it is also become more important for the Integration of Analog & Digital Technology.
Although the High Density Printed Circuit Board Design that constitutes the system does not necessarily have a clock design, there is no doubt that the reliability of the system is based on the selection of electronic components, packaging technology, circuit design and cost, and the consideration of how to prevent noise generation and noise leakage.
High Density Printed Circuit Board Design
Miniaturization, high speed, and multi-function of the machine make low frequency/high frequency, high power signal/low power signal, high output impedance/low output impedance, high current/small current, analog/digital circuit, often appear in the same high package Density board,
Designers in such an environment must face unprecedented design thinking challenges. For example, when a high-stability circuit is adjacent to a noisy circuit, if the counter measures of noise intrusion into a high-stability circuit are not considered as design priorities, Repeated design changes afterwards often become dreams of no solution.
The same is true for the hybrid design of the analog circuit and the high-speed digital circuit. Assuming that the analog signal is amplified, the full scale 5V analog signal is converted into a digital signal by a 10-bit A/D converter. Since the split width is only 4.9mV, it must be read correctly. Taking this voltage level is not an easy task, and as a result, the A/D converter of 10 bits or more faces an unsuccessful operation.
Another typical example is the use of an oscilloscope to measure the ground potential of a digital circuit substrate separated by 10 cm. The ground potential should theoretically be zero. However, in fact, 4.9 mV multiples or even tens of times of pulse noise can be observed. Noise), if the potential difference is caused by the grand of the analog and digital hybrid circuit,
