LD49150

Application hints

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8.8

Heatsinking PPAK package

The PPAK package uses the copper plane on the PCB as a heatsink. The tab of these

packages is soldered to the copper plane for heat sinking. It is also possible to use the PCB

ground plane a heatsink. This area can be the inner GND layer of a multi-layer PCB, or, in a

dual layer PCB, it can be an unbroken GND area on the opposite side where the IC is situated

with a dissipating area thermally connected through vias holes, filled by solder.

Figure 26 shows a curve for

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typical PCB with 1/16 in thick G10/FR4.

8.9

Adjustable regulator design

The LD49150 adjustable version allows fixing output voltage anywhere between 0.8V and 4.5V

using two resistors as shown in the typical application circuit. For example, to fix the R1 resistor

calculated by:

It is suggested to use R1 values lower than 10K

Ω to obtain better load transient performances.

Even, higher values up to 100K

Ω are suitable.

8.10

Enable

The fixed output voltage versions of LD49150 feature an active high Enable input (EN) that

allows on-off control of the regulator. The EN input threshold is guaranteed between 0.4V and

high impedance.

Figure 24.

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