LTC3549 Buck Converter overview
Description
LTC3549 is a 5.50 V sync Buck Converter from with 0.25 A output current. The maximum 5.50 V input voltage can be regulated down into a 0.60 V to 5.00 V output voltage.
It requires are a typical inductor size of 3.30 µH, a typical external component count of 6 and achieves a peak efficiency of 93 %. Further LTC3549 characteristics are a fixed 2250 kHz switching frequency and 1 available package option(s): DFN-6 .
Parameter overview and features with replacement search
For the LTC3549 replacement search, please select a main parameter tolerance value and adjust the checkboxes for feature match. The product counter within the button shows the number of available equivalents and a click on the replacement button shows all possible replacements within a parametric overview.
Parameter | Value | Replacement Search Filter |
V-IN min. | 1.60 V | |
V-IN max. | 5.50 V | |
I-OUT? | 0.25 A | |
V-OUT min. | 0.60 V | |
V-OUT max. | 5.00 V | |
V-OUT | adjustable V | |
V-OUT programmable | ![]() |
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sync/non-sync | sync | |
Frequency typ. | 2250 kHz | |
Frequency | fixed | |
Frequency selectable | ||
ext.clock sync. | ![]() |
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Frequency adj./ ext.clock min. | ||
Frequency adj./ ext.clock max | ||
Softstart | ![]() |
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Softstart adjustable | ![]() |
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Tracking | ![]() |
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PG/Power OK | ![]() |
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Quiescent current max. | 475 µA | |
Operating min. | -40 °C | |
Operating max. | 85 °C | |
Junction min. | ||
Junction max. | ||
thermal shutdown typ. | 150 °C | |
Inductor size typ. | 3.30 µH | |
Inductor suggested by Würth Elektronik | ||
Automotive AEC-Q100 | ![]() |
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Light-Load-Mode | ![]() |
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Topology | Buck | |
Peak Efficiency | 93 % | |
Component count min. | 6 | |
current limit adjustable | ![]() |
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Nr.of packages | 1 | |
CSP | ||
SC70 | ||
SOT | ||
MSOP | ||
QFN/DFN | DFN-6 | |
SO/SOIC | ||
SOP | ||
DIP | ||
TO | ||
DDPAK |
LTC3549 Datasheet
Link to the most up-to-date LTC3549 datasheet and the product page for EVM, tools and support information.
LTC3549 Sample stock and distributor price breaks
LTC3549 prices and online available distributors.


Available Distributors with stock: 0
Available Distributors with stock: 0
List of equivalents and alternatives
The following DC/DC Buck Converter are similar to LTC3549. Optional, compare LTC3549 side-by-side with other Buck Converter via the Comparison function.
Inductor suggestions
Below you can find matching inductors from Wuerth Elektronik calculated on the maximum parameters of LTC3549.
Order Code | Spec | L (µH) | IR (A) | ISAT (A) | RDC (mΩ) | L x W x H (mm) |
74479776233A | 3.3 | 1.3 | 0.3 | 120.00 | 2 x 1.6 x 1 | |
74479787233A | 3.3 | 1.6 | 0.4 | 100.00 | 2.5 x 2 x 1 | |
74479887233A | 3.3 | 1.2 | 0.6 | 180.00 | 2.5 x 2 x 1 |