tim_programmer
New Member
Hi there
I am doing a bit of repair work building a new power supply for an apple airport express as the old one exploded... i'm using the following layout
components
fairchild ka278r05 - 5V 2A low dropout voltage regulator
https://www.electro-tech-online.com/custompdfs/2008/08/KA2FKA278R05C.pdf
tsc ts1086 - 3.3V 1.5A low dropout voltage regulator
https://www.electro-tech-online.com/custompdfs/2008/08/Module2046058.pdf
my plan is to have a standard plug dc psu supply power to the ka278r05 with a 47µF cap on its output to ground (as per the datasheet) have this go to the 5v on the airport express and also act as the input to the ts1086. then have a 10µF cap on the output of the ts1086 (as per datasheet). the ts1086 will provide the 3.3v line needed by the airport express
i only have basic knowledge of electronics so the things i am unsure of...
are the caps values correct ...because i have that cap in the middle of the 2 regulators should its value differ at all?
should i have a cap on the input to the ka278r05?
in the ts1086 datasheet it says i should use a tantalum cap for the 10µF cap
.... do i need to really - i dont have any lying about i have a 10µF 400V rated alu electrolytic handy from the blown psu
reading up on tantalum caps got me all confused with the 2 arguing groups about whether they are good.
if i should go tantalum as suggested by datasheet...does that mean the 47µF should also be a tantalum?
thanks for taking the time to read this over guidance is much appreciated
I am doing a bit of repair work building a new power supply for an apple airport express as the old one exploded... i'm using the following layout
components
fairchild ka278r05 - 5V 2A low dropout voltage regulator
https://www.electro-tech-online.com/custompdfs/2008/08/KA2FKA278R05C.pdf
tsc ts1086 - 3.3V 1.5A low dropout voltage regulator
https://www.electro-tech-online.com/custompdfs/2008/08/Module2046058.pdf
my plan is to have a standard plug dc psu supply power to the ka278r05 with a 47µF cap on its output to ground (as per the datasheet) have this go to the 5v on the airport express and also act as the input to the ts1086. then have a 10µF cap on the output of the ts1086 (as per datasheet). the ts1086 will provide the 3.3v line needed by the airport express
i only have basic knowledge of electronics so the things i am unsure of...
are the caps values correct ...because i have that cap in the middle of the 2 regulators should its value differ at all?
should i have a cap on the input to the ka278r05?
in the ts1086 datasheet it says i should use a tantalum cap for the 10µF cap
.... do i need to really - i dont have any lying about i have a 10µF 400V rated alu electrolytic handy from the blown psu
reading up on tantalum caps got me all confused with the 2 arguing groups about whether they are good.
if i should go tantalum as suggested by datasheet...does that mean the 47µF should also be a tantalum?
thanks for taking the time to read this over guidance is much appreciated