Datasheet

PC Board Layout www.ti.com
5 PC Board Layout
The layout of the printed circuit board is critical to optimize the performance of the LM3492 application
circuit. In general, external components should be placed as close to the LM3492 and each other as
possible in order to make copper traces short and direct. In particular, components of the boost converter
C
IN
, L
1
, D
1
, C
OUT
, and the LM3492 should be closed. Also, the output feedback capacitor C
FB1
should be
closed to the output capacitor C
OUT
. The ground plane connecting the GND, PGND, and LGND pins and
the exposed pad of the LM3492 and the ground connection of the C
IN
and C
OUT
should be placed on the
same copper layer.
Good heat dissipation helps optimize the performance of the LM3492. The ground plane should be used
to connect the exposed pad of the LM3492, which is internally connected to the LM3492 die substrate.
The area of the ground plane should be extended as much as possible on the same copper layer around
the LM3492. Using numerous vias beneath the exposed pad to dissipate heat of the LM3492 to another
copper layer is also a good practice.
6 Bill of Materials
Item Part Number Mfg name Part Description Qty Ref Designator(s) Size
1 GRM31CR61E106KA12L muRata Cap 10 µF 25V X5R 2 C
IN1
, C
IN2
1206
2 GRM188R71C474KA88D muRata 0603/X7R/0.47 µF/16V 1 C
CDHC
0603
3 GRM1885C2A100RA01D muRata 0603/COG/10 pF/100V 1 C
FB1
0603
4 GRM188R71C105KA12D muRata 0603/X7R/1 µF/16V 1 C
VCC
0603
5 GRM32ER72A225KA35L muRata Cap 2.2uF 100V X7R 2 C
O1
, C
O2
1210
6 CRCW060352K3FKEA Vishay Resistor Chip 52.3 kΩ 1 R
COMM
0603
1%
7 CRCW0603274KFKEA Vishay Resistor Chip 274 kΩ 1 R
RT
0603
1%
8 CRCW0603402KFKEA Vishay Resistor Chip 402 kΩ 1 R
FB1
0603
1%
9 CRCW060316K2FKEA Vishay Resistor Chip 16.2 kΩ 1 R
FB2
0603
1%
10 CRCW06038K25FKEA Vishay Resistor Chip 8.25 kΩ 1 R
IREF
0603
1%
11 CRCW06030000Z0EA Vishay Resistor Chip 0Ω 1% 1 R
ILIM0
0603
12 CDRH10D68/ANP-270MC Sumida Inductor 27 µH 1.9A 1 L
1
10×10×6.8
13 SK310A-TP Micro Commercial Schottky 100V 3A 1 D
1
SMA
14 1502-2k-ND KEYSTONE Terminal DBL Turret 11 VIN, GND, PGND,
0.109”L Brass VLED1, VLED2,
IOUT1, IOUT2, DIM1,
DIM2, COMM, EN
15 LM3492EVAL Texas Instruments LM3492 demo board 1 PCB
16 LM3492 Texas Instruments IC LM3492 1 U1 HTSSOP-
20
4
AN-2056 LM3492 Evaluation Board Reference Design SNVA438B–September 2010–Revised April 2013
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