I want 4 bit digital input for presetting of counter 74ls192.How can I do such task using Analog to digital converter? Is there any specific IC available for 4 bits ADC? Or do i need to design ADC using comparator and resistors? THANK YOU!
2 Answers
You probably can't buy an off-the-shelf 4-bit ADC. But you can buy an 8-bit parallel-out ADC and just ignore the 4 lsb's of the output.
That will almost certainly be cheaper (in money, board area, and power) than building your own 4-bit ADC from comparators.
The simplest solution would be to use the four most-significant bits of an 8-bit ADC.
Figure 1. 8-bit ADC with oscillator based on the TI ADC0804. Source: Electro-Tech Online.