LM3429MH National Semiconductor, LM3429MH Datasheet - Page 22

• Manufacturer Part Number: LM3429MH
• Description: IC, LED DRIVER, CNTRL, 14TSSOP
• Manufacturer: National Semiconductor

Specifications of LM3429MH

• Led Driver Application: Automotive, General Illumination
• No. Of Outputs: 1
• Output Current: 1A
• Input Voltage: 4.5V To 75V
• Dimming Control Type: Analogue / PWM
• Topology: Boost, Buck, Buck-Boost, SEPIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Design Example #1
BUCK-BOOST APPLICATION - 6 LEDs at 1A
SPECIFICATIONS
N = 6
V
r
V
V
V
f
V
I
Δi
Δi
Δv
I
V
V
V
V
1. OPERATING POINT
Solve for V
SW
LED
LIM
LED
LED
IN
IN-MIN
IN-MAX
SNS
TURN-ON
HYS
TURN-OFF
HYSO
L-PP
LED-PP
IN-PP
= 24V
= 700 kHz
= 6A
= 1A
= 325 mΩ
= 3.5V
= 100 mV
= 3V
= 500 mA
= 10V
= 10V
= 1V
= 70V
= 50 mA
= 10V
= 40V
O
and r
D
:
22
Solve for D, D', D
2. SWITCHING FREQUENCY
Assume C
The closest standard resistor is actually 35.7 kΩ therefore the
f
The chosen components from step 2 are:
SW
is:
T
= 1 nF and solve for R
MAX
, and D
MIN
:
T
:
300944i1