Hey folks,
I'm working on a project which uses Texas Instruments CD4011BE NAND IC's. I'm finding a lot of them are going into the bucket due to them not working properly. I've been designing a circuit for the past couple of months, and have finished prototyping each component area of the overall circuit, and everything has been going well. Now however, i'm tryinig to get the main logic brain of my circuit working and have found that out of about 22 NAND chips i've bought, only 2 actually work in my circuit. I need four in total to work the whole thing. I've ordered another 16 from a seller on Ebay and i'm waiting for delivery later this week.
The two I have which work on one half of my circuit, i've moved between positions to the other half of the circuit, and have proven that they work wherever I put them. But as I say, these are TWO....of around 22! Out of the failing ones, I've resisted throwing about 10 of them straight into the bucket, and gone through the laborious exercise of testing them with a multi meter instead; testing each NAND gate in turn with all four permutations of input possible states. From this testing, I threw 4 away because I confirmed that, for whatever reason, one or more of the gates wasn't working properly. This left me with 6 (in addition to the 2 working ones) which tested fine with my multi meter testing, yet they still wont work with my circuit!? I'm most confused!!!??
Has anyone else had a great amount of difficulty with these chips? Am I destroying them with static even though i'm gingerly handling them with kid gloves, touching only the back plastic body? (I've not got a static mat or wrist band, and with the two which i've got working, i've intentionally "man handled" them in between proof tests on my circuit, to see if I could intentionally damage them with my hands, but they keep on ticking no problem, so this leads me to suspect that all the others shouldn't be that sensitive either!?) I've been doing things like touching radiator piping etc in the house before touching the chips in an attempt to ground myself etc just to try and be as static free as possible. But as I stress, only 2 keep working fine. All the others refuse to work.
any help/advice?
I'm working on a project which uses Texas Instruments CD4011BE NAND IC's. I'm finding a lot of them are going into the bucket due to them not working properly. I've been designing a circuit for the past couple of months, and have finished prototyping each component area of the overall circuit, and everything has been going well. Now however, i'm tryinig to get the main logic brain of my circuit working and have found that out of about 22 NAND chips i've bought, only 2 actually work in my circuit. I need four in total to work the whole thing. I've ordered another 16 from a seller on Ebay and i'm waiting for delivery later this week.
The two I have which work on one half of my circuit, i've moved between positions to the other half of the circuit, and have proven that they work wherever I put them. But as I say, these are TWO....of around 22! Out of the failing ones, I've resisted throwing about 10 of them straight into the bucket, and gone through the laborious exercise of testing them with a multi meter instead; testing each NAND gate in turn with all four permutations of input possible states. From this testing, I threw 4 away because I confirmed that, for whatever reason, one or more of the gates wasn't working properly. This left me with 6 (in addition to the 2 working ones) which tested fine with my multi meter testing, yet they still wont work with my circuit!? I'm most confused!!!??
Has anyone else had a great amount of difficulty with these chips? Am I destroying them with static even though i'm gingerly handling them with kid gloves, touching only the back plastic body? (I've not got a static mat or wrist band, and with the two which i've got working, i've intentionally "man handled" them in between proof tests on my circuit, to see if I could intentionally damage them with my hands, but they keep on ticking no problem, so this leads me to suspect that all the others shouldn't be that sensitive either!?) I've been doing things like touching radiator piping etc in the house before touching the chips in an attempt to ground myself etc just to try and be as static free as possible. But as I stress, only 2 keep working fine. All the others refuse to work.
any help/advice?