High-speed ADC, what is a high-speed ADC for answers

ADC, like computers, has gone through a low-speed to high-speed development process. ADC's low-speed (conversion time greater than 300uS ) structure of the integral type, ramp type, tracking type; ADC's medium-speed (conversion time of 1uS-300uS ) structure of the successive approximation type; ADC's high-speed (conversion time of less than 1uS ) structure of the scintillation type, partitioning, and the high-resolution structure of ∑∑ -△ type. -△ type. These different structures to meet the wide range of practical applications and the diversity of needs, in which high-speed ADC has become an important link in determining the performance of modern electronic equipment such as radar, communications, electronic countermeasures, aerospace, missiles, measurement and control, ground exhibition, medical, instrumentation, graphics, high-performance controllers and digital communication systems.

Basic principle: the current high-speed ADC is mainly used in the following two structural forms. One is the fully parallel structure, also called Flash structure. ADCs of this structure have at least 2"-1 comparators, for example, an eight-bit ADC has at least 255 comparators. When the ADC resolution increases, not only the circuit volume is huge, and power consumption soars, but also prone to "spark code", and therefore generally used for lower resolution ADCs, such as six-bit, eight-bit ADCs. Another form of structure is called partitioned or folded structure, such as two-step method, multi-step method. The circuit structure mainly contains S/H (or T/H) amplifier, Flash A/D converter, time scale circuit and digital error correction circuit. Partitioned structure ADC to overcome the pure Flash structure ADC with the increase in resolution, the circuit is large, power consumption soared the shortcomings but brings another problem, that is, the differential amplifier and which the second conversion processing input voltage related circuitry introduced errors, these errors will exceed the converter allows the error, and must be introduced to the digital error correction.