jhanus
New Member
Hello,
I'm using demux 74ls138, and I'm having big problems with it.
For settings:
ENABLE = 1..................|=>now 74ls138 is working in decoder mode
Both inverted ENABLE=0 |
for any adress exepct A2=0, A1=0, A0=0 I have correct values.
When I have logical 1 on expected output I see 4.10V which is good.
When I have logical 0 on expected output I see 1.41V which is also good.
But, when I set adress A2=0, A1=0, A0=0 on output Y0 I see this:
When I have logical 1 on Y0 I see 2.84V which is not good.
When I have logical 0 on Y0 I see 0.15V which is good, but diffrent from other output values.
First I thought that I burned the first one, so I bought another one, but this 74ls138 shows same behavior.
I tried first with no load, then with load(I=~14mA), same results.
So I'm doing something wrong, but what?!
Please help it's somehow urgent, thanks.
I'm using demux 74ls138, and I'm having big problems with it.
For settings:
ENABLE = 1..................|=>now 74ls138 is working in decoder mode
Both inverted ENABLE=0 |
for any adress exepct A2=0, A1=0, A0=0 I have correct values.
When I have logical 1 on expected output I see 4.10V which is good.
When I have logical 0 on expected output I see 1.41V which is also good.
But, when I set adress A2=0, A1=0, A0=0 on output Y0 I see this:
When I have logical 1 on Y0 I see 2.84V which is not good.
When I have logical 0 on Y0 I see 0.15V which is good, but diffrent from other output values.
First I thought that I burned the first one, so I bought another one, but this 74ls138 shows same behavior.
I tried first with no load, then with load(I=~14mA), same results.
So I'm doing something wrong, but what?!
Please help it's somehow urgent, thanks.