LX1996 Datasheet, PDF (19/22 Pages) Microsemi Corporation – Multi-string LED Back-light Controller

LX1996
TM
®
Multi-string LED Back-light Controller
PRODUCTION DATASHEET
PCB LAYOUT RECOMMENDATIONS
(SEE FIGURE 2 SCHEMATIC)
PCB LAYOUT GUIDE
It is recommended that decoupling capacitors C7 and C4 be placed as close as possible to the LX1996. The Inductor current sense
resistor R1 must tie directly to PGND pin, and then tie to the power ground plane at that pin.
For a good practical layout of switching boost circuit, keep loops as short as possible for the boost switching components ( Q1,
L1, D1, & C3). Connect a separate signal ground plane to GND pin, a separate power ground plane to PGND pin, and then tie
them together at GND pin.
It is important that the LX1996 have a good thermal path to ambient to dissipate heat. The simplest way to do this is to heat sink
the LX1996 bottom pad directly to the ground plane by placing 4 or more vias in the ground pad directly under the LX1996
footprint.
Place the LDO filter capacitor (C5), R5 (R_T resistor), C2 (C_T capacitor), C1 (C_LF capacitor), and R4 (R_PRG resistor) as close to the
IC as practical.
PCB LAYOUT GUIDE – TOP LAYER
Actual PCB size (H x W): 10mm x 40mm
Copyright © 2007
Rev. 1.0, 2007-12-14
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
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