LM3429MH National Semiconductor, LM3429MH Datasheet - Page 24
LM3429MH
Manufacturer Part Number
LM3429MH
Description
IC, LED DRIVER, CNTRL, 14TSSOP
Manufacturer
National Semiconductor
Datasheet
1.LM3429MHNOPB.pdf
(34 pages)
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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Company
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Manufacturer
Quantity
Price
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LM3429MH
Manufacturer:
NS/国半
Quantity:
20 000
Company:
Part Number:
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Manufacturer:
NS/TI
Quantity:
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Part Number:
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T
To ensure stability, calculate ω
Solve for C
To attenuate switching noise, calculate ω
Assume R
The chosen components from step 7 are:
8. INPUT CAPACITANCE
Solve for the minimum C
To minimize power supply interaction a 200% larger capaci-
tance of approximately 14 µF is used, therefore the actual
Δv
selection is limited, three 4.7 µF X7R capacitors are chosen.
Determine minimum allowable RMS current rating:
The chosen components from step 8 are:
U0
IN-PP
is approximated:
is much lower. Since high voltage ceramic capacitor
FS
CMP
= 10Ω and solve for C
:
IN
:
P2
:
FS
:
P3
:
24
9. NFET
Determine minimum Q1 voltage rating and current rating:
A 100V NFET is chosen with a current rating of 32A due to
the low R
The chosen component from step 9 is:
10. DIODE
Determine minimum D1 voltage rating and current rating:
A 100V diode is chosen with a current rating of 12A and V
600 mV. Determine P
The chosen component from step 10 is:
11. INPUT UVLO
Solve for R
The closest standard resistor is 150 kΩ therefore V
Solve for R
DS-ON
UV2
UV1
:
:
= 50 mΩ. Determine I
D
:
T-RMS
and P
T
:
HYS
is:
D
=