Datasheet
TPS62060
V = 1.8 V
up to 1.6 A
OUT
R
360 k
1
Ω
R
180 k
2
Ω
V = 2.7 V to 6 V
IN
C
10
OUT
µF
C
10
IN
µF
PVIN
AVIN
EN
MODE
AGND
PGND
SW
FB
C
22 pF
ff
L
1.0 H
µ
V
OUT
+ V
REF
ǒ
1 )
R
1
R
2
Ǔ
f
p´ ´ ´
z
1 ff
1
= = 25 kHz
2 R C
p´ ´ ´
ff
1
1
C =
2 R 25 kHz
c
1
= = 50kHz
2 (1μH 10μF)
f
p´ ´ ´
DI
L
+ Vout
1 *
Vout
Vin
L ƒ
TPS62061, TPS62063
TPS62060
www.ti.com
SLVSA95A –MARCH 2010– REVISED JANUARY 2011
APPLICATION INFORMATION
Figure 23. TPS62060 1.8V Adjustable Output Voltage Configuration
OUTPUT VOLTAGE SETTING
The output voltage can be calculated to:
with an internal reference voltage V
REF
typically 0.6V.
To minimize the current through the feedback divider network, R
2
should be within the range of 120 kΩ to 360
kΩ. The sum of R
1
and R
2
should not exceed ~1MΩ, to keep the network robust against noise. An external
feed-forward capacitor Cff is required for optimum regulation performance. Lower resistor values can be used.
R1 and Cff places a zero in the loop. The right value for Cff can be calculated as:
Therefore, the feed forward capacitor can be calculated to:
OUTPUT FILTER DESIGN (INDUCTOR AND OUTPUT CAPACITOR)
The internal compensation network of TPS62060 is optimized for a LC output filter with a corner frequency
of:
The part operates with nominal inductors of 1.0µH to 1.2 µH and with 10µF to 22µF small X5R and X7R ceramic
capacitors. Please refer to the lists of inductors and capacitors. The part is optimized for a 1.0µH inductor and
10µF output capacitor.
Inductor Selection
The inductor value has a direct effect on the ripple current. 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
or V
O
.
Equation 1 calculates the maximum inductor current in PWM mode under static load conditions. The saturation
current of the inductor should be rated higher than the maximum inductor current as calculated with Equation 2.
This is recommended because during heavy load transient the inductor current rises above the calculated value.
(1)
Copyright © 2010–2011, Texas Instruments Incorporated 15