Datasheet
L
Lmax outmax
I
I = I +
2
D
L
Vout
1
Vin
I = Vout
L
-
D ´
´ ¦
1.2V
V
OUT
2.05V-6V
V
IN
2.2 Fm
C
IN
L
1/2.2 Hm
C
4.7 F
OUT
m
TPS62232
VIN
EN
MODE
SW
FB
GND
1.8V
V
OUT
2.05V-6V
V
IN
2.2 Fm
C
IN
L
1/2.2 Hm
C
4.7 F
OUT
m
TPS62231
VIN
EN
MODE
SW
FB
GND
TPS62230
L
1/2.2 Hm
VIN
EN
MODE GND
FB
SW
2.5V
V
OUT
2.7V-6V
V
IN
2.2
C
IN
mF
4.7 Fm
C
OUT
TPS62230, TPS62231, TPS62232, TPS62233, TPS62234, TPS62235, TPS62236
TPS62237, TPS62238, TPS62239, TPS622310, TPS622311, TPS622312
TPS622313, TPS622314, TPS622315, TPS622316, TPS622317, TPS622318
www.ti.com
SLVS941E –APRIL 2009–REVISED DECEMBER 2010
APPLICATION INFORMATION
Figure 52. TPS62230 2.5V Output
Figure 53. TPS62231 1.8V Output
Figure 54. TPS62232 1.2V Output
OUTPUT FILTER DESIGN (INDUCTOR AND OUTPUT CAPACITOR)
The TPS6223X is optimized to operate with effective inductance values in the range of 0.7μH to 4.3μH and with
effective output capacitance in the range of 2.0μF to 15μF. The internal compensation is optimized to operate
with an output filter of L = 1.0μH/2.2μH and C
OUT
= 4.7μF. Larger or smaller inductor/capacitor values can be
used to optimize the performance of the device for specific operation conditions. For more details, see the
CHECKING LOOP STABILITY section.
INDUCTOR SELECTION
The inductor value affects its peak-to-peak ripple current, the PWM-to-PFM transition point, the output voltage
ripple and the efficiency. The selected inductor has to be rated for its dc resistance and saturation current. The
inductor ripple current (ΔI
L
) decreases with higher inductance and increases with higher V
I N
or V
O UT
. Equation 5
calculates the maximum inductor current under static load conditions. The saturation current of the inductor
should be rated higher than the maximum inductor current as calculated with Equation 6. This is recommended
because during heavy load transient the inductor current will rise above the calculated value.
(5)
(6)
With:
f = Switching Frequency
L = Inductor Value
ΔI
L
= Peak to Peak inductor ripple current
I
Lmax
= Maximum Inductor current
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