My recommendation is to use the OKI. 3-Terminal TO-220 DC-DC regulator.
It is a drop in replacement for the linear LDO and more efficient and not expensive.
X—x-x-x-x
By entering parameters like All TO-220 packages or 5V 2 to 3 A you can easily find solutions from a variety of disti’s.
e.g.
Then use a heat sink rated for 2x the Vdrop max x 2A= Pd to avoid a dreaded max temp. input unregulated voltage drops with rising current so the Vdrop min must be satisfied by the LDO . BJT types are 1.5V to 2V while FET types are <1V typically but may cost more.
Matching LDO voltages ensures parallel current sharing is equal but thermal connections between all of them improves power sharing and cooling.
- e.g. of load regulation error is 1% and voltage tolerance is 1% you may have to add a small series R to each that equals the mismatched voltage and shared current to normalize them at the tradeoff of increased Rs/load = max load regulation error.
Say 1% V = 50mV and 1% Load error = 50mv with a 2.5 Ohm=5V/2A load implies source R =25 mOhms so adding 25 mOhms in series reduces the max variation in half meaning the sharing improves 50%. Now determine how many are sharing you need and add extra to account for imbalance to avoid thermal runaway from hogging. If load drops the highest regulator within the initial tolerance, then the others will share current. So adding this Rs improves the sharing but with slight added drop in voltage but still within 5%.
ok I lost you... but that’s how it’s done.
you see the same in power amps after complementary Darlingtons. With 0.1 Ohm or less added to each driver. This normalizes or linearizes the output impedance. Although Amps use negative feedback to then lower the impedance again, which you cannot do with a 3 terminal regulator.