LM3429BSTEVAL/NOPB National Semiconductor, LM3429BSTEVAL/NOPB Datasheet - Page 6

• Manufacturer Part Number: LM3429BSTEVAL/NOPB
• Description: BOARD EVAL FOR BOOST LM3429
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM3429BSTEVAL/NOPB

• Current - Output / Channel: 1A
• Outputs And Type: 1, Non-Isolated
• Features: Dimmable
• Voltage - Input: 10 ~ 26 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
• Msl: MSL 1 - Unlimited
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• Voltage - Output: -
• Other names: *LM3429BSTEVAL; *LM3429BSTEVAL/NOPB; LM3429BSTEVAL

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5. OUTPUT CAPACITANCE
Solve for C
A total value of 6.6 µF (using 3 2.2 µF X7R ceramic capaci-
tors) is chosen therefore the actual Δi
Determine minimum allowable RMS current rating:
The chosen components from step 5 are:
6. PEAK CURRENT LIMIT
Solve for R6:
The closest standard resistor is 0.04 Ω therefore I
The chosen component from step 6 is:
7. LOOP COMPENSATION
ω
ω
P1
Z1
is approximated:
is approximated:
O
:
LED-PP
is:
LIM
is:
6
T
To ensure stability, calculate ω
Solve for C8:
Since PWM dimming can be evaluated with this board, a
much larger compensation capacitor C8 = 1.0 µF is chosen.
To attenuate switching noise, calculate ω
Assume R20 = 10Ω and solve for C12:
The chosen components from step 7 are:
8. INPUT CAPACITANCE
Solve for the minimum C
To minimize power supply interaction a much larger capaci-
tance of approximately 20 µF is used, therefore the actual
Δv
selection is limited, four 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
IN
:
P2
:
P3
: