Texas Instruments TLV62080EVM-756 Evaluation Module TLV62080EVM-756 TLV62080EVM-756 Datenbogen
Produktcode
TLV62080EVM-756
SW
IN
OUT
OUT
L
L
MAX
,
OUT
MAX
,
L
f
L
V
V
1
V
I
2
I
I
I
´
-
´
=
D
D
+
=
SLVSAK9E – OCTOBER 2011 – REVISED FEBRUARY 2014
9.2.2 Detailed Design Procedure
Table 3. List of Components
REFERENCE
DESCRIPTION
MANUFACTURER
C1
10
μF, Ceramic Capacitor, 6.3 V, X5R, size 0603
Std
22
μF, Ceramic Capacitor, 6.3 V, X5R, size 0805,
C2
Murata
GRM21BR60J226ME39L
47
μF, Tantalum Capacitor, 8 V, 35 mΩ, size 3528,
C3
Kemet
T520B476M008ATE035
1
μH, Power Inductor, 2.2 A, size 3 mm × 3 mm × 1.2 mm,
L1
Coilcraft
XFL3012-102MEB
R1
65.3 k
Ω, Chip Resistor, 1/16 W, 1%, size 0603
Std
R2
39.2 k
Ω, Chip Resistor, 1/16 W, 1%, size 0603
Std
R3
178 k
Ω, Chip Resistor, 1/16 W, 1%, size 0603
Std
9.2.2.1 Output Filter Design
The inductor and the output capacitor together provide a low pass frequency filter. To simplify this process
outlines possible inductor and capacitor value combinations for the most application.
Table 4. Matrix of Output Capacitor and Inductor Combinations
C
OUT
[µF]
(1)
L [µH]
(1)
10
22
47
100
150
0.47
1
+
+
(2) (3)
+
+
2.2
+
+
+
+
4.7
(1)
Capacitance tolerance and bias voltage de-rating is anticipated. The effective capacitance can vary by
+20% and –50%. Inductor tolerance and current de-rating is anticipated. The effective inductance can
vary by +20% and –30%.
+20% and –50%. Inductor tolerance and current de-rating is anticipated. The effective inductance can
vary by +20% and –30%.
(2)
Plus signs (+) indicates recommended filter combinations.
(3)
Filter combination in typical application.
9.2.2.2 Inductor Selection
Main parameter for the inductor selection is the inductor value and then the saturation current of the inductor. To
calculate the maximum inductor current under static load conditions,
calculate the maximum inductor current under static load conditions,
is given.
Where
•
I
OUT,MAX
= Maximum output current
•
ΔI
L
= Inductor current ripple
•
f
SW
= Switching frequency
•
L = Inductor value
(2)
TI recommends choosing the saturation current for the inductor 20% to approximately 30% higher than the I
L,MAX
,
out of
. A higher inductor value is also useful to lower ripple current, but increases the transient
response time as well. The following inductors are recommended to be used in designs (see
).
12
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