Resistors values for LT1074 buck converter

Status
Not open for further replies.
J

jmx66

Member level 5
Joined
Nov 16, 2010
Messages
93
Helped
0
Reputation
0
Reaction score
1
Trophy points
1,288
Location
France
Activity points
2,045
Hi all,

I only want to get resistor values R3, R4 and R5, to get 16V and ≈ 2A output.

In fact, i'd like to know how to compute them, as schematics found were with Common emitter, Base and so on, so with power supply between Base and Emitter by example.

In this schematic, Base is linked to ground ??



View attachment AN44-LT1074-Design-Manual.pdf

Thanks a lot.

jm
 

The app note defines the requirements.
"The voltage across R4 is set at 1.1V by R3, which is connected to the output"

ILIM = Desired output current limit. ILIM should be set ≈1.25 times maximum load current to allow for variations in VBE and component tolerances.


RS=(R4*IX +VBE)/( ILIM/100–IX)

IX = VOUT + VBE + 0.4mA

I didn't go beyond this. good luck
 
Reactions: jmx66

    J

    jmx66

    Points: 2
    Helpful Answer Positive Rating
Hi SunnySkyguy,

Thanks a lot for your reply, in fact i found it also in datasheet, but thought there was other stuff .... It seemed me too simple.

Now i can end my spreadsheet with this reply :grin::grin:

You are right: LDO regulators and smps are muuuuch more efficient:smile::smile: than linear :---(

Regards.


jm
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…