China
Africa
Explore chapters and articles related to this topic
Data Conversion
Published in Mike Tooley, Aircraft Digital Electronic and Computer Systems, 2023
The priority encoder is a logic device that produces a binary output code that indicates the value of the most significant logic 1 received on one of its inputs. In this case, the output of IC2 will be the most significant logic 1 and hence the binary output code generated will be 010, as shown in Figure 3.9b. Flash ADC are extremely fast in operation (hence the name), but they become rather impractical as the resolution increases. For example, an 8-bit flash ADC would require 256 operational amplifier comparators and a 10-bit device would need a staggering 1,024 comparator stages! Typical conversion times for a flash ADC lie in the range 50 ns to 1 μs, so this type of ADC is ideal for ‘fast’ or rapidly changing analogue signals. Due to their complexity, flash ADC are relatively expensive.
Gate-Level Modeling
Published in Joseph Cavanagh, ® HDL Digital Design and Modeling, 2017
Unlike a regular encoder, a priority encoder can have more than one input asserted simultaneously. Priority encoders are typically used in a time-sharing system. The outputs indicate the input that has the highest priority; that is, if two lines xiand xj, where i > j, request service simultaneously, then line xi has priority over line xj and the outputs will indicate the binary number corresponding to i. In general, there are n input lines and log2n output lines, as shown below. log2n=y2y=n
D/A and A/D Converters
Published in Jerry D. Gibson, The Communications Handbook, 2018
The functional blocks of a flash A/D converter are shown in Fig. 9.2. The circuitry consists of a precision resistor ladder network, 2n-1 analog comparators, and a digital priority encoder. The resistor network establishes threshold voltages for each allowed quantization level. The analog comparators indicate whether the input analog voltage is above or below the threshold at each level. The output of the analog comparators is input to the digital priority encoder. The priority encoder produces the final digital output code that is stored in an output latch.
Design and Analysis of Memristor-based Combinational Circuits
Published in IETE Journal of Research, 2020
The encoder produces the m-bit binary code corresponding to the n-bit digital input code. A priority encoder is a special type of encoder in that upon giving two or more inputs at the same time, the input having the highest priority takes precedence. According to the most significant bit of input available, the encoder output represents the binary equivalent of the ordinal number (Figure 2, Table 1).