LM3409 Datasheet, PDF (20/30 Pages) National Semiconductor (TI) – PFET Buck Controller for High Power LED Drives

8. INPUT UVLO
Solve for R_UV2:
The closest 1% tolerance resistor is 6.98 kΩ therefore V_TURN-
ON ^is:
The closest 1% tolerance resistor is 49.9 kΩ therefore V_HYS
is:
Solve for R_UV1:
The chosen components from step 8 are:
Design #1 Bill of Materials
Qty
Part ID
1
LM3409HV
2
C_IN1, C_IN2
1
C_F
1
C_OFF
1
Q1
1
D1
1
L1
1
R_OFF
1
R_UV1
1
R_UV2
1
R_SNS
9. IADJ CONNECTION METHOD
The IADJ pin is left open forcing V_ADJ = 1.24V.
10. PWM DIMMING METHOD
PWM dimming signal pair is applied to the EN pin and GND
at f_DIM = 1 kHz.
Part Value
Buck controller
2.2µF X7R 10% 100V
Manufacturer
NSC
MURATA
1.0µF X7R 10% 16V
470pF X7R 10% 50V
PMOS 100V 3.8A
Schottky 100V 3A
15 µH 20% 4.2A
24.9kΩ 1%
6.98kΩ 1%
49.9kΩ 1%
0.1Ω 1% 1W
TDK
TDK
ZETEX
VISHAY
TDK
VISHAY
VISHAY
VISHAY
VISHAY
Part Number
LM3409HVMY
GRM43ER72A225KA01
L
C1608X7R1C105K
C1608X7R1H471K
ZXMP10A18KTC
SS3H10-E3/57T
SLF12565T-150M4R2
CRCW060324K9FKEA
CRCW06036K98FKEA
CRCW060349K9FKEA
WSL2512R1000FEA
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