A replacement for LP2950CZ

[Astromic]

Hi,
I'm building the mini pin pointer featured on EPE magazine issue July 2003, the circuit contains a 5V low dropout positive regulator LP2950CZ. I could't find that specific IC here anywhere, so is there any close match to replace it with?
Thanks'

Mike

[ivconic]

Hi,
I'm building the mini pin pointer featured on EPE magazine issue July 2003, the circuit contains a 5V low dropout positive regulator LP2950CZ. I could't find that specific IC here anywhere, so is there any close match to replace it with?
Thanks'

Mike

If you intend to use 9v battery than simple 78L05 should do a job. Not exactly a low drop, but there will be enough voltage difference in such case.
Cheers!

[Skippy]

You do need low dropout, as two Lithium cells can easily fall below 6V in use. But the current draw is very low, so there are a number of choices, such as ST-micro LE50CZ, Natsemi LM2931Z-5, Texas TL750L05, best to double check this list.

[Astromic]

hmm, about the battery i would loooooove to go AA or AAA or else(9v is good?),, I did a humble search due to my knowledge -not a pro- and found the LM3480(5v version) is quite similar to the LP2950CZ, both are 5V 100mA and low dropout, but the LP2950 is a "positive" type regulator, the LM3480 is unknown .. well, at least to me of course .
I'm afraid to use something that might fry the parts or something, not likely with that voltage, but as i said, i'm not a pro! so what do you think guys?
http://www.ti.com/lit/ds/symlink/lm3480.pdf

Mike

[Astromic]

Well, I can go with something else other than those cells, AA or AAA or even 9v would be perfect, actually don't need it to be exactly "mini" anyway.. I did a humble research myself, and found that there is another close match to the LP2950CZ, which is the Lm3480, a 5V low dropout 100mV output.. Is it another good candidate or am i missing something in the datasheets?
Thanks'

Mike

[jap]

Hi Astromic
-I agreed with the view of ivconic.(The 78L05 easiest)
-If you will be using Lm3480-5 --- care pin numbers and installation method.
-see link: http://www.geotech1.com/forums/showt...ood-Pinpointer
Wishes Mike .
best time
j.

[Astromic]

Thanks' jap,
Now i will search for one of these: 78L05, TL750L05, LE50CZ, LM2931Z-5.. I hope i just find the 78L05 as you recommended first place.
Thanks'

Mike

[Astromic]

Done
I've replaced it with the 78L05, it worked great, it seems that with the 9v it runs more stable and sensitive than the two 3V..
I used 2 coils for testing, the first is a 20mm 100 turns by 0.26mm enameled wire as a pinpointer, it start to sing for a 15mm coin at 60mm distance, and can detect smaller targets like 3mm iron nut at 20mm distance. I see it's a very decent result for a pinponter, and might get better with another specific coil. The other coil is a 100mm one, 27 turns of the same wire, it can detect the same coin at 100mm, not so good but i believe it is due to wrong turns, i will try to play a little and fine tune the results for an optimum one, but for testing only, as the project is for learning and fun only.
One thing i would recommend if anyone intend to build it, don't use a preset pots, because the device is very sensitive and can vary the tune rapidly when holding the device near the coil or the pots themselves, so both pots should have knobs to fine tune regularly. I will try to post pictures soon..
Thanks' for your help guys.

Mike