LM3429BKBSTEVAL National Semiconductor, LM3429BKBSTEVAL Datasheet - Page 20
![no-image](/images/manufacturer_photos/0/4/469/national_semiconductor_sml.jpg)
LM3429BKBSTEVAL
Manufacturer Part Number
LM3429BKBSTEVAL
Description
BOARD, EVALUATION, FOR LM3429
Manufacturer
National Semiconductor
Datasheet
1.LM3429MHNOPB.pdf
(34 pages)
Specifications of LM3429BKBSTEVAL
Kit Contents
LM3429 Assembled Evaluation Board, Application Note, LM3429 Datasheet
Svhc
No SVHC (15-Dec-2010)
Kit Features
Drives 4 To 8 LED At Max Average LED Current 1A, Overvoltage Protection,
www.national.com
A high frequency compensation pole (ω
attenuate switching noise and provide better gain margin. As-
suming R
value of the pole and the RHP zero of the system (shown as
a maximizing function):
The total system loop gain (T) can then be written as:
Buck
Boost and Buck-boost
8. INPUT CAPACITANCE
Set the nominal input voltage ripple (Δv
the required capacitance (C
Buck
Boost
Buck-boost
Use D
solving for C
solving for C
The minimum allowable RMS input current rating (I
can be approximated:
Buck
Boost
MAX
FS
to set the worst case input voltage ripple, when
= 10Ω, C
IN
IN
in a buck-boost regulator and D
in a buck regulator.
FS
is calculated according to the higher
IN
):
IN-PP
P3
) can be used to
) by solving for
MID
= 0.5 when
CIN-RMS
)
20
Buck-boost
9. NFET
The NFET voltage rating should be at least 15% higher than
the maximum NFET drain-to-source voltage (V
Buck
Boost
Buck-boost
The current rating should be at least 10% higher than the
maximum average NFET current (I
Buck
Boost and Buck-boost
Approximate the nominal RMS transistor current (I
Buck
Boost and Buck-boost
Given an NFET with on-resistance (R
nominal power dissipation (P
10. DIODE
The Schottky diode voltage rating should be at least 15%
higher than the maximum blocking voltage (V
Buck
Boost
Buck-boost
T
):
T-MAX
DS-ON
):
), solve for the
RD-MAX
T-MAX
T-RMS
):
):
) :