LM3429BKBSTEVAL/NOPB National Semiconductor, LM3429BKBSTEVAL/NOPB Datasheet - Page 5
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LM3429BKBSTEVAL/NOPB
Manufacturer Part Number
LM3429BKBSTEVAL/NOPB
Description
BOARD EVAL FOR BUCK-BOOST LM3429
Manufacturer
National Semiconductor
Series
PowerWise®r
Specifications of LM3429BKBSTEVAL/NOPB
Current - Output / Channel
1A
Outputs And Type
1, Non-Isolated
Features
Dimmable
Voltage - Input
10 ~ 70 V
Utilized Ic / Part
LM3429
Core Chip
LM3429
Topology
Buck-Boost
No. Of Outputs
1
Dimming Control Type
PWM / Analog
Development Tool Type
Hardware - Eval/Demo Board
Mcu Supported Families
LM3429 Family
Lead Free Status / RoHS Status
Lead free by exemption / RoHS compliant by exemption
Voltage - Output
-
Other names
*LM3429BKBSTEVAL
*LM3429BKBSTEVAL/NOPB
LM3429BKBSTEVAL
*LM3429BKBSTEVAL/NOPB
LM3429BKBSTEVAL
Design Procedure
Refer to LM3429 datasheet for design considerations.
SPECIFICATIONS
N = 6
V
r
V
V
f
V
I
Δi
Δi
Δv
I
V
V
1. OPERATING POINT
Solve for V
Solve for D, D', D
2. SWITCHING FREQUENCY
Assume C7 = 1 nF and solve for R10:
The closest standard resistor is actually 35.7 kΩ therefore the
f
The chosen components from step 2 are:
LED
SW
LED
LIM
SW
LED
IN
IN-MIN
SNS
TURN-ON
TURN-OFF
L-PP
LED-PP
IN-PP
= 24V
= 700 kHz
is:
= 5A
= 1A
= 325 mΩ
= 3.5V
= 100 mV
= 500 mA
= 10V; V
= 100 mV
= 50 mA
= 10V; V
= 60V; V
O
and r
IN-MAX
MAX
D
HYS
HYSO
:
, and D
= 70V
= 3V
= 15V
MIN
:
5
3. AVERAGE LED CURRENT
Solve for R9:
Assume R1 = 12.4 kΩ and solve for R8:
The closest standard resistor for R9 is 0.1Ω and the closest
for R8 (and R7) is actually 1 kΩ therefore I
The chosen components from step 3 are:
4. INDUCTOR RIPPLE CURRENT
Solve for L1:
The closest standard inductor is 33 µH therefore the actual
Δi
Determine minimum allowable RMS current rating:
The chosen component from step 4 is:
L-PP
is:
LED
is:
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