Texas Instruments LM3269 User Manual
2.2 PH
PVIN
PVIN
EN
SGND PGND
SW1 SW2
LM3269
VOUT
FB
VCON
V
OUT
: 0.6V to 4.2V
4.7 PF
10 PF
VIN: 2.7V to 5.5V
GPO1
BB RFIC
DAC
V
OUT
= 3 x VCON
RF
PA
1 Introduction
The LM3269 evaluation board is a working demonstration of a buck-boost DC-DC converter designed to
generate output voltages above or below a given input voltage. It is particularly suitable for cell-phone
applications powering 3G/4G Power Amplifiers.
For more details and electrical characteristics about the converter operation, please refer to the LM3269
data sheet. If you are considering using the LM3269 in a system design, please review the "PCB Layout
Considerations” section of the data sheet.
2 Operating Conditions
The device will operate under the following conditions:
• VIN: 2.7V ≤ VIN≤ 5.5V
• Adjustable V
• VCON: 0.2V to 1.4V
• V
• I
equation: V
OUT
range: 0mA to 750mA
OUT
: 0.6V to 4.2V
OUT
= 3 x VCON
OUT
User's Guide
SNVU162–FEBRUARY 2013
LM3269 Evaluation Board
3 Package
The LM3269 is available in a 12-bump (0.4 mm pitch) lead-free DSBGA (2.0mm X 2.5mm X 0.6mm)
package.
4 Typical Application Circuit
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Startup Sequence
5 Startup Sequence
To activate the LM3269EVM Buck-Boost DC-DC converter output, execute the following steps:
1. Place EN pin LOW.
2. Power up PVIN (within the P
3. Set VCON pin to 1/3 of desired output voltage (0.2 ≤ VCON ≤ 1.4V).
4. Place EN pin HIGH, then V
6 List of Materials
Designator Model Description Manufacturer
(1)
CPVIN
(2)
C1
(2)
C2
C3 C1608X5R0J106K 10 μF, 6.3V, 0603 (1608)
C4 C1608X5R0J475K 4.7 μF, 6.3V, 0603 (1608) Std
(2)
C5
(2)
C6
(3)
C7, C8
C9 Std Optional, 0402 (1005) Std
L MIPSZ2520D2R2 2.2 μH, 2.5 x 2.0 x 1.0 mm FDK
R1 Std Optional, 01005 (0402), Shorted Std
U1 LM3269TLE Buck-Boost Converter Texas Instruments
(1)
CPVIN: The long test leads necessary for bench testing add significant parasitic inductances in series with the bench power
supply. The 100 μF capacitor at CPVIN reduces the impact that these parasitic inductances have on both static and transient
behavior during testing.
(2)
C1, C2, C5, C6 help to improve high frequency noise.
(3)
C7, C8 resemble PA decoupling capacitor.
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range of 2.7V to 5.5V).
VIN
should present as expected.
OUT
Std Std
100 μF, optional , 6.3V, 1411 (3528)
Low ESR Tantalum
Std 220 pF, optional, 01005 (0402) Std
Std 0.1 μF, optional, 0201 (0603)
TDK
Std 0.1μF, optional, 0201 (0603) Std
Std 220 pF, optional, 01005 (0402) Std
Std 0.47 μF, optional, 0201 (0603) Std
7 Input/Output Capacitor Information
The total recommended actual capacitance on the VOUT bus should be at least 7.0 μF (4.7 μF + PA
decoupling caps) to take into account the DC bias degradation and other tolerances.
BUS MIN (µF) TYP (µF) MAX (µF)
PVIN – 10 –
VOUT 7 – 10
2
LM3269 Evaluation Board SNVU162–FEBRUARY 2013
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EN
SGND
PGND
SW
1
SW2
LM3269
VOUT
FB
VCON
VOUT: 0.6V to 4.2V
C1
SW1
SW2
VIN: 2.7V to 5.5V
jumper
CPVIN
C2
+
2.2 µH
C3
10 µF
C4
4.7 µF
C5
C6
C8
C7
to RF PA
VIN
R1
shorted
C9
VCON
input
PVIN
PVIN
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8 Evaluation Board Schematic and PCB Layout
Figure 1. Picture of LM3269 Evaluation Board
Evaluation Board Schematic and PCB Layout
Figure 2. LM3269 Evaluation Board Schematic
SNVU162–FEBRUARY 2013 LM3269 Evaluation Board
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