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sinara-hw / AUX_PSU

Low noise, 3-channel, regulated power supply module
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LT3089IFE - too high dropout voltage - extra power dissipation #15

Closed mkiepiela closed 2 weeks ago

mkiepiela commented 2 years ago

Dropout voltage at both LDOs is unnecessarily set too high (more than 3.9 V) causing extra power dissipation (even 1.5 - 2 W extra power on each LDO).

According to the LDO spec 2 V would be more than enough. Set R13/R24 and R18/R14.

obraz

gkasprow commented 1 year ago

I added 120k in parallel to R24, R14 and now the dropout is 1.7V

gkasprow commented 1 year ago

negative LDO is already 2V

gkasprow commented 1 year ago

we need to leave them 120k