Discussion in 'The Projects Forum' started by Rajit28, Oct 29, 2008.
How do we make a R2R ladder network wor?
Take a look in the AAC ebook.
How does 7493 IC connect to this network.
at output or input.
A 7493 is a binairy counter and connects at the input of the dac.
More information on dac / adc conversions can be found in the EDUCYPEDIA.
everyone's advice was very helpful.
is 7493 a 4 or 8 bit DAC.
i need a 4 bit DAC?
The 7493 is a counter, not a DAC.
Just adding to Thingmaker's comment,
The 7493 is a 4-bit binary up-counter.
If you're going to use an R2R ladder on the outputs to create a ramp generator, I suggest that you use the 74HC93.
Whether the ramp slopes up or slopes down depends upon how you connect the R2R ladder to the outputs of the '93 counter.
See the attached for a similar idea.
The LF351 is used as a buffer amplifier. It was really not a good choice for this application, because the inputs and outputs are not rail to rail, but it works OK for the first 14 of the 16 discrete steps. Since CMOS logic has very limited output current, the R2R values need to be rather high; so a buffer amplifier is necessary for all but very high impedance outputs.
The LM339 provides a means to terminate the ramp early, by resetting the counter.
The 4020 is a CMOS dual binary up-counter.
any recommendations for buffer amplifiers welcome.
any one know where to find buffer amplifiers.
Would any of the following suffice?
thanks for everyone'shelp this thread can be closed.
The LF351 is this a good buffer amplifier?
do you know the website for buffer amplifiers?
Best place to find clocks for 7493 IC chips.
the clock measures pulse length in micro seconds i think
Do you need a clock source? You can find clock oscillators with logic outputs in 4 pin IC packages. A 1 MHz oscillator will give microsecond timing.
do you know where to get 4 pin IC packages. in my college we normally
use 16 pins or 8 pins or something 4 pins looks a little small
don't you think?
4 pins was good. thanks to help of forum
my project was successful.