Datasheet

( ) ( )
= - ´
TH TOT
A max J max
T T R P
= + ´
J A TH TOT
T T R P
= + + + = + + + =
TOT COND SW GD Q
P P P P P 0.47 W 0.123 W 0.022 W 0.0018 W 0.616 W
TPS54360
www.ti.com SLVSBB4E –AUGUST 2012–REVISED MARCH 2014
Where:
I
OUT
is the output current (A).
R
DS(on)
is the on-resistance of the high-side MOSFET (Ω).
V
OUT
is the output voltage (V).
V
IN
is the input voltage (V).
ƒsw is the switching frequency (Hz).
trise is the SW terminal voltage rise time and can be estimated by trise = V
IN
x 0.16ns/V + 3.0ns.
Q
G
is the total gate charge of the internal MOSFET.
I
Q
is the operating nonswitching supply current.
Therefore,
(53)
For given T
A
,
(54)
For given T
JMAX
= 150°C
(55)
Where:
Ptot is the total device power dissipation (W).
T
A
is the ambient temperature (°C).
T
J
is the junction temperature (°C).
R
TH
is the thermal resistance of the package (°C/W).
T
JMAX
is maximum junction temperature (°C).
T
AMAX
is maximum ambient temperature (°C).
There will be additional power losses in the regulator circuit due to the inductor ac and dc losses, the catch diode
and PCB trace resistance impacting the overall efficiency of the regulator.
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