Datasheet

LPSMload
II D=
2
1
)(
TPS62160
TPS62161, TPS62162, TPS62163
SLVSAM2C –NOVEMBER 2011–REVISED SEPTEMBER 2013 www.ti.com
where
I
L
(max) is the maximum inductor current,
ΔI
L
is the Peak to Peak Inductor Ripple Current,
L(min) is the minimum effective inductor value and
f
SW
is the actual PWM Switching Frequency.
Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation
current of the inductor needed. A margin of about 20% is recommended to add. A larger inductor value is also
useful to get lower ripple current, but increases the transient response time and size as well. The following
inductors have been used with the TPS6216X and are recommended for use:
Table 2. List of Inductors
Type Inductance [µH] Current [A]
(1)
Dimensions [L x B x H] mm MANUFACTURER
VLF3012ST-2R2M1R4 2.2µH, ±20% 1.9A 3.0 x 2.8 x 1.2 TDK
VLF302512MT-2R2M 2.2µH, ±20% 1.9A 3.0 x 2.5 x 1.2 TDK
VLS252012T-2R2M1R3 2.2uH, ±20% 1.3A 2.5 x 2.0 x 1.2 TDK
XFL3012-222MEC 2.2µH, ±20% 1.9A 3.0 x 3.0 x 1.2 Coilcraft
XFL3012-332MEC 3.3µH, ±20% 1.6A 3.0 x 3.0 x 1.2 Coilcraft
LPS3015-332ML_ 3.3uH, ±20% 1.4A 3.0 x 3.0 x 1.4 Coilcraft
NR3015T-2R2M 2.2uH, ±20% 1.5A 3.0 x 3.0 x 1.5 Taiyo Yuden
744025003 3.3uH, ±20% 1.5A 2.8 x 2.8 x 2.8 Wuerth
PSI25201B-2R2MS 2.2uH, ±20% 1.3A 2.0 x 2.5 x 1.2 Cyntec
(1) I
RMS
at 40°C rise or I
SAT
at 30% drop.
spacing
The TPS6216X can be run with an inductor as low as 2.2µ H. However, for applications with low input voltages,
3.3µH is recommended, to allow the full output current. The inductor value also determines the load current at
which Power Save Mode is entered:
(9)
Using Equation 8, this current level can be adjusted by changing the inductor value.
Capacitor Selection
Output Capacitor
The recommended value for the output capacitor is 22uF. The architecture of the TPS6216X allows the use of
tiny ceramic output capacitors with low equivalent series resistance (ESR). These capacitors provide low output
voltage ripple and are recommended. To keep its low resistance up to high frequencies and to get narrow
capacitance variation with temperature, it's recommended to use X7R or X5R dielectric. Using a higher value can
have some advantages like smaller voltage ripple and a tighter DC output accuracy in Power Save Mode (see
SLVA463).
Note: In power save mode, the output voltage ripple depends on the output capacitance, its ESR and the peak
inductor current. Using ceramic capacitors provides small ESR and low ripple.
Input Capacitor
For most applications, 10µF will be sufficient and is recommended, though a larger value reduces input current
ripple further. The input capacitor buffers the input voltage for transient events and also decouples the converter
from the supply. A low ESR multilayer ceramic capacitor is recommended for best filtering and should be placed
between VIN and GND as close as possible to those pins.
spacing
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