Author Topic: Replacing 7XL12 with drop in LDO LT3045

February 09, 2023, 03:30:02 AM
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paranoidandroid

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Hi, I'm thinking of building this kit and was wondering if any part values would need to be adjusted if I replaced the voltage regulators with this LDO drop in replacement: https://www.ldovr.com/Ultra-Low-Noise-Low-Dropout-Voltage-Regulator-p/lt3045-78xx.htm
Obviously use the 79 equivalent part as well, this would allow for +-15 operation from the 500 series PSU. Any thoughts? Thanks!

February 09, 2023, 09:58:11 AM
Reply #1

JPK

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What I understand from the link you supplied, is that these regulators are made of a switching regulator followed by a linear regulator. They can only be more noisy than a simple linear regulator.
Also the pins layout is different from the 78L12.
The noise generated by the 78L12/79L12 is already filtered by R102/C52 and R103/C55. You could increase the caps values if you want to improve the filtering.
JPK

February 09, 2023, 04:20:10 PM
Reply #2

paranoidandroid

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Thanks for the response, as long as I don't need to adjust any other component values, I'll give them both a shot and increase filtering as you suggested. Pinout is reversed, but should just involve a 180 flip right?

February 09, 2023, 07:13:42 PM
Reply #3

JPK

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The PCB holes are not in line but make a triangle
JPK