ACE1117H

1A Bipolar Linear Regulator

VER 1.2

7

Thermal Considerations

We have to take heat dissipation into great consideration when output current or differential voltage of

input and output voltage is large. Because in such cases, the power dissipation consumed by ACE1117H is

very large. ACE1117H series uses SOT-223 package type and its thermal resistance is about 20°C/W.

And the copper area of application board can affect the total thermal resistance. If copper area is 5cm*5cm

(two sides), the resistance is about 30°C/W. So the total thermal resistance is about 20°C/W + 30°C/W. We

can decrease total thermal resistance by increasing copper area in application board. When there is no

good heat dissipation copper are in PCB, the total thermal resistance will be as high as 120°C/W, then the

power dissipation of ACE1117H could allow on itself is less than 1W. And furthermore, ACE1117H will work

at junction temperature higher than 125°C under such condition and no lifetime is guaranteed.

Typical Performance Characteristic

ACE1117H-ADJ Vout vs. Vin

Vin(V)

ACE1117H-ADJ Vout vs. Iout

Iout(A)