LM3429MH/NOPB National Semiconductor, LM3429MH/NOPB Datasheet - Page 22

• Manufacturer Part Number: LM3429MH/NOPB
• Description: IC LED DRVR HP CONS CURR 14TSSOP
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: High Power, Constant Currentr

Specifications of LM3429MH/NOPB

• Constant Current: Yes
• Topology: PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Automotive
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 2MHz
• Voltage - Supply: 4.5 V ~ 75 V
• Mounting Type: Surface Mount
• Package / Case: 14-TSSOP Exposed Pad, 14-eTSSOP 14-HTSSOP
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 1A
• Internal Switch(s): No
• Efficiency: 95%
• For Use With: LM3429BSTEVAL - BOARD EVAL FOR BOOST LM3429LM3429BKBSTEVAL - BOARD EVAL FOR BUCK-BOOST LM3429
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Other names: LM3429MH

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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