Datasheet

HG
BOOT
I
SEN
LG
PGND
FB
V
CC
SD
PWGD
FREQ
SS/TRACK
SGND
EAO
PGND
V
CC
= V
IN
= 3.3V
V
OUT
= 1.8V@2A
R
FB2
C
C2
R
C1
R
CS
C
SS
R
FADJ
R
CC
C
CC
D
1
C
BOOT
Q1
C
IN
1,2
L1
+
C
C1
R
FB1
C
O
1,2
LM2743
R
C2
C
C3
R
PULL-UP
+
K =
4.8W
4.8W + 0.6W
= 89%
K =
P
OUT
P
OUT
+ P
TOTAL
x 100%
LM2743
SNVS276G –APRIL 2004–REVISED MARCH 2013 www.ti.com
Total System Efficiency
P
TOTAL
= P
FET
+ P
IC
+ P
GATE
+ P
CAP
+ P
IND
Example Circuits
Figure 39. 3.3V to 1.8V @ 2A, f
SW
= 300kHz
Table 1. Bill of Materials
PART PART NUMBER TYPE PACKAGE DESCRIPTION VENDOR
U1 LM2743 Synchronous TSSOP-14 TI
Controller
Q1 FDS6898A Dual N-MOSFET SOIC-8 20V, 10mΩ@ 4.5V, Fairchild
16nC
D1 MBR0520LTI Schottky Diode SOD-123
L1 DO3316P-472 Inductor 4.7µH, 4.8Arms 18mΩ Coilcraft
C
IN
1 16SP100M Aluminum Electrolytic 10mm x 6mm 100µF, 16V, 2.89Arms Sanyo
C
O
1 6SP220M Aluminum Electrolytic 10mm x 6mm 220µF, 6.3V 3.1Arms Sanyo
C
CC
, C
BOOT,
VJ1206Y104KXXA Capacitor 1206 0.1µF, 10% Vishay
C
IN
2, C
O
2
C
C3
VJ0805Y332KXXA Capacitor 805 3300pF, 10% Vishay
C
SS
VJ0805A123KXAA Capacitor 805 12nF, 10% Vishay
C
C2
VJ0805A821KXAA Capacitor 805 820pF 10% Vishay
C
C1
VJ0805A220KXAA Capacitor 805 22pF, 10% Vishay
R
FB2
CRCW08051002F Resistor 805 10.0kΩ 1% Vishay
R
FB1
CRCW08054991F Resistor 805 4.99kΩ1% Vishay
R
FADJ
CRCW08051103F Resistor 805 110kΩ 1% Vishay
R
C2
CRCW08052101F Resistor 805 2.1kΩ 1% Vishay
R
CS
CRCW08052101F Resistor 805 2.1 kΩ 1% Vishay
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