Datasheet

Startup Sequence www.ti.com
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
VIN
range of 2.7V to 5.5V).
3. Set VCON pin to 1/3 of desired output voltage (0.2 ≤ VCON ≤ 1.4V).
4. Place EN pin HIGH, then V
OUT
should present as expected.
6 List of Materials
Designator Model Description Manufacturer
100 μF, optional , 6.3V, 1411 (3528)
CPVIN
(1)
Std Std
Low ESR Tantalum
C1
(2)
Std 220 pF, optional, 01005 (0402) Std
C2
(2)
Std 0.1 μF, optional, 0201 (0603)
TDK
C3 C1608X5R0J106K 10 μF, 6.3V, 0603 (1608)
C4 C1608X5R0J475K 4.7 μF, 6.3V, 0603 (1608) Std
C5
(2)
Std 0.1μF, optional, 0201 (0603) Std
C6
(2)
Std 220 pF, optional, 01005 (0402) Std
C7, C8
(3)
Std 0.47 μF, optional, 0201 (0603) Std
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.
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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