Datasheet

DI
L
+ V
O
1 *
V
O
V
I
L f
I
L
(max) + I
O
(max) )
DIL
2
f = Switching frequency (850 kHz typical)
L = Inductor value
∆IL = Peak-to-peak inductor ripple current
I
L
(max) = Maximum inductor current
TPS62052, TPS62054
TPS62056, TPS62050, TPS62051
SLVS432E –SEPTEMBER 2002–REVISED JUNE 2011 www.ti.com
LAYOUT AND BOARD SPACE
All capacitors should be soldered as close as possible to the IC.
For information on the PCB layout see the user's guideSLVU081.
Keep the feedback track as short as possible. Any coupling to the FB pin may cause additional output voltage
ripple.
INDUCTOR SELECTION
A 10-µH minimum inductor should be used with the TPS6205x. Values larger than 22 µH or smaller than 10 µH
may cause stability problems due to the internal compensation of the regulator. After choosing the inductor value
of typically 10 µH, two additional inductor parameter should be considered: the current rating of the inductor and
the dc resistance. The dc resistance of the inductance directly influences the efficiency of the converter.
Therefore, an inductor with lowest dc resistance should be selected for highest efficiency. In order to avoid
saturation of the inductor, the inductor should be rated at least for the maximum output current plus half the
inductor ripple current which is calculated as:
The highest inductor current occurs at maximum VIN . A more conservative approach is to select the inductor
current rating just for the maximum switch current of the TPS6205x which is 1.4 A maximum. See Table 3 for
inductors that have been tested for operation with the TPS6205x.
Table 3. Inductors
MANUFACTURER TYPE INDUCTANCE DC RESISTANCE SATURATION CURRENT
SLF7032T-
10 µH ±20% 53 mΩ ±20% 1.4 A
100M1R4SLF7032T-
22 µH ±20% 110 mΩ ±20% 0.96 A
TDK 220M96SLF7045T-
10 µH ±20% 36 mΩ ±20% 1.3 A
100M1R3SLF7045T-
22 µH ±20% 61 mΩ ±20% 0.9 A
100MR90
CDR74B 10 µH 70 mΩ 1.65 A
CDR74B 22 µH 130 mΩ 1.12 A
CDH74 10 µH 49 mΩ 1.8 A
CDH74 22 µH 110 mΩ 1.23 A
Sumida
CDR63B 10 µH 140 mΩ 1 A
CDRH4D28 10 µH 128 mΩ 1 A
CDRH5D28 10 µH 48 mΩ 1.3 A
CDRH5D18 10 µH 92 mΩ 1.2 A
DT3316P-153 15 µH 60 mΩ 1.8 A
Coilcraft
DT3316P-223 22 µH 84 mΩ 1.5 A
WE-PD 744 778 10 10 µH 72 mΩ 1.68 A
WE-PD 744 777 10 10 µH 49 mΩ 1.84 A
Wuerth
WE-PD 744 778 122 22 µH 190 mΩ 1.07A
WE-PD 744 777 122 22 µH 110 mΩ 1.23 A
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