LM3743_08 Datasheet, PDF (24/28 Pages) National Semiconductor (TI) – High-Performance Synchronous Buck Controller with Comprehensive Fault Protection Features

Example Circuit 1
LM3743-300, V_IN = 5V, V_OUT = 1.5V, I_LOAD = 20A
FIGURE 12. Schematic
201774b2
Designator
U1
C1
C2, C11
C3
C4
C5
C6
C7
C8
C9
C10
R1
R2
R3
R4
R5
R6
L1
D1
D2
Q1
Q2
Function
Controller
Input Filter
Input Filter
Decoupling
Soft Start Cap
Output Filter
Output Filter
Comp Cap
Comp Cap
Comp Cap
Bootstrap Cap
Current Limit Res
Top FB Resistor
Bottom FB Res
Comp Resistor
Comp Resistor
Vcc Filter Resistor
Output Filter
Bootstrap Diode
LSPSD
Top FET
Bottom FET
Description
Buck Controller
22µF,10V, X7R, 1210
POSCAP, 6V, 470µF
1µF, 10V, X7R, 0805
180nF, 25V, 0805
680µF, 2.5V, 5mΩ
150nF, 25V, 0805
22pF, 25V, 0603
680pF, 25V, 0603
1.5nF, 25V, 0603
.47µF, 25V, 0805
1.4k, 0603
24.9k, 0603
28k, 0603
49.9k, 0603
3.32k, 0603
2 ohm, 0603
1.2µH, DCR = 2.9mΩ
500mA, 20V, VF =.3V
IF=2A,VR=20V,VF =.3V
3.6mΩ@VGS=4.5V,
24.5nC
1.7mΩ@VGS=4.5V,
61nC
Part Number
LM3743MSOP-10
1206ZD227MAT
6TPD470M
0805ZC105KAT
VJ0805Y184KXXA
2R5TPD680M5
VJ0805Y154KXXA
VJ0603A220KXAA
VJ0603A681KXAA
VJ0603Y152KXXA
VJ0805Y474KXXA
CRCW06031401F
CRCW06032492F
CRCW06032802F
CRCW06034992F
CRCW06033321F
CRCW06032R00F
SER2009-122ML
MBR0520LT1
SL22
Si7136DP
Vendor
National Semiconductor
AVX
Sanyo
AVX
Vishay
Sanyo
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Vishay
Coilcraft
Onsemi
Vishay
Vishay
Si7470DP
Vishay
R3 = 7.87 kΩ (Vout = 3.3V), 11.5 kΩ (Vout = 2.5V), 19.6 kΩ (Vout = 1.8V), 28 kΩ (Vout = 1.5V), 49.9 kΩ (Vout = 1.2V), 100 kΩ (Vout = 1.0V), open (Vout = 0.8V)
www.national.com
24