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How EPROM works with DAC?

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sherline123

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Hello.I am a student. I am designing a shaping filter in my project. In my idea, I am going to cut the desired waveform shape into few sample poinnts and store at EPROM. Hence, I am able to get the values stored from EPROM by inserting corresponding address. After this, it will pass through a DAC and all the sample points will be connected. As I know, EPROM only allow the output to be '0' or '1'. If i store it in binary value, e.g 4 = 0100; how can the DAC decode it 0100 and get 4 as my final output?
 

EPROM is an OTP memory. I have no idea how you can use it.
0100 ~ 4 placed to 8 bit DAC powered from 5V will give 5*4/256 volts on output after sync pulse
 

thanks for the explanations. i am going to program it by using an universal programmer.
 

First you need an address counter to cycle through the entire address range of the EPROM sequentially.

That address will create an output at the EPROM depending what you originally programmed into it at each address.

A digital to analog converter then generates an output waveform that corresponds to the data programmed into the EPROM.

One thing you need to be aware of.

There will be a small time delay between when the address changes, and when the EPROM output data is stable. While the EPROM is looking up the next address, there will be a short burst of completely random rubbish on the output.

The digital to analog converter must be clocked to only accept the new data after it is stable and correct.
 

I have done exactly this, making modulation waveforms.
Built up with HC series CMOS, 25xx UV EPROMS and a
poor-boy RDAC using HCMOS inverters and discrete
resistors.

5V EPROMs are slow. OTP "EPROMs" (no window) I
found were inferior speed grade and no good for my
data rate. Willem programmer is what I used. Your
question about how to get "4" is really about output
scaling, probaby you want a buffer / amp after your
DAC which can filter glitches and scale / shift output
from DAC full scale to analog full scale ranges.

Re-registering EPROM outputs before DAC digital input
can help with glitching, especially if all bits are in one
octal DFF you can expect good alignment.
 
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