Datasheet
0.5
2 OUT
μs
L = V × ×
A
( )
0.5
1 IN1 OUT
μs
L = V V × ×
A
-
L1
VIN
VINA
EN
PS
GND
L2
VOUT
FB
PGND
L1
C2
C1
V
IN
V
OUT
TPS6301X
SYNC
VSEL
VINA1
C3
R2
R1
R
1
+ R
2
ǒ
V
OUT
V
FB
* 1
Ǔ
TPS63010
TPS63011
TPS63012
www.ti.com
SLVS653B –JUNE 2008–REVISED MAY 2012
APPLICATION INFORMATION
DESIGN PROCEDURE
The TPS6301x dc/dc converters are intended for systems powered by one-cell Li-Ion or Li-Polymer battery with a
typical voltage between 2.3 V and 4.5 V. They can also be used in systems powered by a double or triple cell
Alkaline, NiCd, or NiMH battery with a typical terminal voltage between 2 V and 5.5 V . Additionally, any other
voltage source with a typical output voltage between 2 V and 5.5 V can power systems where the TPS6301x is
used.
PROGRAMMING THE OUTPUT VOLTAGE
Within the TPS6301X family there are fixed and adjustable output voltage versions available. To properly
configure the fixed output voltage devices, the FB pin is used to sense the output voltage. This means that it
must be connected directly to V
OUT
. At the adjustable output voltage versions, an external resistor divider is used
to adjust the output voltage. The resistor divider must be connected between VOUT, FB and GND. When the
output voltage is regulated properly, the typical value of the voltage at the FB pin is 500 mV. The maximum
recommended value for the output voltage is 5.5 V. The current through the resistive divider should be about 100
times greater than the current into the FB pin. The typical current into the FB pin is 0.01 μA, and the voltage
across the resistor between FB and GND, R2, is typically 500 mV. Based on those two values, the
recommended value for R2 should be lower than 500 kΩ, in order to set the divider current at 1 μA or higher.
The recommended value for this resistor is in the range of 200 kΩ. From that, the value of the resistor connected
between VOUT and FB, R1, depending on the needed output voltage (V
OUT
), is calculated using Equation 1:
(1)
As an example, if an output voltage of 3.3 V is needed, a 1-MΩ resistor should be chosen for R1 if R2 is 180-kΩ.
Figure 31. Typical Application Circuit for Adjustable Output Voltage Option
INDUCTOR SELECTION
To properly configure the TPS6301X devices, an inductor must be connected between pin L1 and pin L2. To
estimate the inductance value Equation 2 and Equation 3 can be used.
(2)
(3)
Copyright © 2008–2012, Texas Instruments Incorporated Submit Documentation Feedback 19
Product Folder Link(s): TPS63010 TPS63011 TPS63012