Datasheet
APPLICATION INFORMATION
ADJUSTABLE OUTPUT VOLTAGE VERSION
O
R1
V = 0.45 V 1 +
R2
æ ö
´
ç ÷
è ø
(1)
47
2
(ff) o
1
C = for C F
30000 R1
m
p
<
´ ´
(2)
47
2 5
(ff) o
1
C = for C F
000 R1
m
p
³
´ ´
(3)
V
IN
1
8
6
7
3 2
9
5
10
4
L1 =10 mH
EN
ILIM
SYNC
GND FC
PG
PGND
FB
L
TPS62000
+
C
o
=10 mF
V
O
=2.5V/600mA
C3=0.1 mF
C
i
=10 mF
V
I
=2.7Vto5.5V
R3=320kΩ
R1=820kΩ
C
(ff)
=
6.8pF
R2=180kΩ
+
PG
INDUCTOR SELECTION
TPS62000, TPS62001, TPS62003
TPS62004, TPS62005, TPS62006
TPS62007, TPS62008
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........................................................................................................................................... SLVS294E – SEPTEMBER 2000 – REVISED AUGUST 2008
When the adjustable output voltage version (TPS62000DGS) is used, the output voltage is set by the external
resistor divider (see Figure 15 ).
The output voltage is calculated as:
With R1 + R2 ≤ 1 M Ω
R1 + R2 should not be greater than 1 MW because of stability reasons.
For stability reasons, a small bypass capacitor (Cff) is required in parallel to the upper feedback resistor, refer to
Figure 15 . The bypass capacitor value can be calculated as:
R1 is the upper resistor of the voltage divider. For C
(ff)
, choose a value which comes closest to the computed
result.
Figure 15. Typical Application Circuit for Adjustable Output Voltage Option
A 10 µ H minimum output inductor is used with the TPS6200x. Values larger than 22 µ H or smaller than 10 µ H
may cause stability problems because of the internal compensation of the regulator.
For output voltages greater than 1.8 V, a 22 µ H inductance might be used in order to improve the efficiency of
the converter.
After choosing the inductor value of typically 10 µ H, two additional inductor parameters should be considered:
first the current rating of the inductor and second the dc resistance.
The dc resistance of the inductance influences directly 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 the inductor ripple current which is calculated as:
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