Timeline for Voltage drop with 2 LM317 in parallel/different output voltages
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Oct 5, 2021 at 20:22 | history | edited | JRE | CC BY-SA 4.0 |
deleted 40 characters in body
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| Oct 5, 2021 at 20:20 | history | edited | nhouse | CC BY-SA 4.0 |
added 204 characters in body
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| Sep 18, 2021 at 16:21 | comment | added | Martin Vana | Interestingly everyone talks here about 2.5V minimum voltage drop but checking with TI datasheet I see "Minimum recommended voltage headroom 3V". Doesn't change the essence of the question but may be good to qualify. LM317 may be produced by various manufacturers and the voltage headroom doesn't necessarily answer only "does it work" but also "how well it performs". ti.com/lit/ds/symlink/… | |
| Sep 18, 2021 at 14:17 | answer | added | Transistor | timeline score: 5 | |
| Sep 18, 2021 at 14:13 | comment | added | user24368 | Hi! Could you please add a schematic of the circuit to the original question? Usually a picture tells more than a 1000 words. If I understand correctly, you are correct, just as @glen_geek says. The 2.5 V is needed for the voltage regulation. | |
| Sep 18, 2021 at 14:12 | comment | added | jay | It needs only 2.5V headroom, since VI is common to both of the regulators. 3V may be better: "8.4.2 Operation With Low Input Voltage The device requires up to 3-V headroom (V I – V O ) to operate in regulation. The device may drop out and OUTPUT voltage will be INPUT voltage minus drop out voltage with less headroom." | |
| Sep 18, 2021 at 14:07 | comment | added | glen_geek | Schematics are better than words, but your 2 beliefs are very likely correct. | |
| S Sep 18, 2021 at 14:01 | review | First questions | |||
| Sep 18, 2021 at 14:13 | |||||
| S Sep 18, 2021 at 14:01 | history | asked | nhouse | CC BY-SA 4.0 |