FAN5340 Datasheet, PDF (2/12 Pages) Fairchild Semiconductor – Synchronous Constant-Current Series Boost LED Driver with PWM Brightness Control and Integrated Load Disconnect

Block Diagrams
VIN
CIN
PGND
EN
GND
L1
Q1
GATE
DRIVE
BOOST
CONTROL
SW
Q2
D1
VOUT
Q3
VLED
C_OUT
2–4
LEDs
Figure 2. Block Diagram
FB
RSET ^{15 -}
133Ω
Table 1. Recommended External Components
Component
Description
Vendor
Parameter Min. Typ. Max.
Units
L1
22μH Nominal
Murata
L⁽¹⁾
LQH3NPN220MGOK _{DCR (Series R)}
22
1100
μH
mΩ
COUT
4.7μF X5R or Better
C
4.7
μF
CIN
4.7μF X5R or Better
C
4.7
μF
Note:
1. Minimum L (inductance) incorporates tolerance, temperature, and DC bias effects (L decreases with increasing current).
© 2010 Fairchild Semiconductor Corporation
FAN5340 • Rev. 1.0.1
2
www.fairchildsemi.com