RT2858B Buck Converter overview
Description
RT2858B is a 18.00 V sync Buck Converter from with 3.00 A output current. The maximum 18.00 V input voltage can be regulated down into a 0.77 V to 7.00 V output voltage.
It requires are a typical inductor size of 1.40 µH, a typical external component count of 9 and achieves a peak efficiency of 95 %. Further RT2858B characteristics are a fixed 650 kHz switching frequency and 1 available package option(s): PSOP-8 .
Parameter overview and features with replacement search
For the RT2858B 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. | 4.50 V | |
V-IN max. | 18.00 V | |
I-OUT? | 3.00 A | |
V-OUT min. | 0.77 V | |
V-OUT max. | 7.00 V | |
V-OUT | adjustable V | |
V-OUT programmable | ![]() |
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sync/non-sync | sync | |
Frequency typ. | 650 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. | 1300 µA | |
Operating min. | -40 °C | |
Operating max. | 85 °C | |
Junction min. | -40 °C | |
Junction max. | 125 °C | |
thermal shutdown typ. | 150 °C | |
Inductor size typ. | 1.40 µH | |
Inductor suggested by Würth Elektronik | ||
Automotive AEC-Q100 | ![]() |
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Light-Load-Mode | ![]() |
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Topology | Buck | |
Peak Efficiency | 95 % | |
Component count min. | 9 | |
current limit adjustable | ![]() |
|
Nr.of packages | 1 | |
CSP | ||
SC70 | ||
SOT | ||
MSOP | ||
QFN/DFN | ||
SO/SOIC | ||
SOP | PSOP-8 | |
DIP | ||
TO | ||
DDPAK |
RT2858B Datasheet
Link to the most up-to-date RT2858B datasheet and the product page for EVM, tools and support information.
RT2858B Sample stock and distributor price breaks
RT2858B prices and online available distributors.


Available Distributors with stock: 0
Available Distributors with stock: 3
Digi-Key
Product | Stock | Price | Buy | ||||||||||||||
RT2858BHGSP | 2996 |
| Buy Now | ||||||||||||||
RT2858BHGSP | 2996 |
| Buy Now | ||||||||||||||
RT2858BHGSP | 0 | Buy Now |
element14 Asia-Pacific
Product | Stock | Price | Buy | ||||||||||||||
RT2858BHGSP | 0 |
| Buy Now | ||||||||||||||
RT2858BHGSP | 500 |
| Buy Now |
Farnell element14
List of equivalents and alternatives
The following DC/DC Buck Converter are similar to RT2858B. Optional, compare RT2858B 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 RT2858B.
Order Code | Spec | L (µH) | IR (A) | ISAT (A) | RDC (mΩ) | L x W x H (mm) |
74404042010 | 1.0 | 3.2 | 4.8 | 27.00 | 4 x 4 x 1.8 | |
74404052010 | 1.0 | 3.9 | 5.5 | 19.80 | 5 x 5 x 2 | |
74404052012 | 1.2 | 3.6 | 5.2 | 23.40 | 5 x 5 x 2 | |
74404052015 | 1.5 | 3.3 | 4.9 | 25.70 | 5 x 5 x 2 | |
74404054015 | 1.5 | 4.3 | 6.9 | 15.00 | 5 x 5 x 4 | |
74404063010 | 1.0 | 5.2 | 7.5 | 10.00 | 6 x 6 x 2.8 | |
74404063015 | 1.5 | 4.6 | 6.6 | 13.00 | 6 x 6 x 2.8 | |
744062001 | 1.0 | 4.8 | 4.6 | 10.00 | 6.8 x 6.8 x 2.5 | |
7440620015 | 1.5 | 4.3 | 4.0 | 10.00 | 6.8 x 6.8 x 2.5 | |
7440650015 | 1.5 | 7.2 | 7.5 | 7.30 | 10 x 10 x 3.1 | |
7440690010 | 1.0 | 3.6 | 3.8 | 21.00 | 8 x 8 x 1.5 | |
7440700012 | 1.2 | 4.8 | 4.2 | 12.50 | 8 x 8 x 2 | |
74408941010 | 1.0 | 3.0 | 5.4 | 29.50 | 4.8 x 4.8 x 2.1 | |
74408942012 | 1.2 | 3.2 | 5.5 | 22.00 | 4.8 x 4.8 x 3.1 | |
74408943010 | 1.0 | 3.3 | 6.5 | 19.00 | 4.8 x 4.8 x 4.1 | |
74437321015 | 1.5 | 3.0 | 4.0 | 55.00 | 4.45 x 4.06 x 1.2 | |
74438336010 | 1.0 | 4.0 | 5.0 | 26.00 | 3 x 3 x 2 | |
74438336012 | 1.2 | 3.9 | 4.8 | 30.00 | 3 x 3 x 2 | |
74438336015 | 1.5 | 3.7 | 4.5 | 33.00 | 3 x 3 x 2 | |
7447730 | 1.0 | 4.0 | 5.7 | 14.00 | 4 x 4.5 x 3.5 | |
744773014 | 1.4 | 3.4 | 5.0 | 22.00 | 4 x 4.5 x 3.5 | |
74477790015 | 1.5 | 4.3 | 7.3 | 15.00 | 7.3 x 7.3 x 4.5 | |
744778001 | 1.0 | 5.4 | 6.4 | 9.00 | 7.3 x 7.3 x 3.4 | |
7447785001 | 1.0 | 3.5 | 4.5 | 31.00 | 5.9 x 6.2 x 3.3 | |
7447786001 | 1.0 | 5.0 | 5.5 | 28.00 | 5.9 x 6.2 x 5.1 | |
7447789001 | 1.0 | 5.4 | 6.4 | 10.00 | 7.3 x 7.3 x 3.5 | |
744787012 | 1.2 | 4.9 | 6.0 | 8.50 | 7.8 x 7 x 5 | |
74479299210 | 1.0 | 3.0 | 5.2 | 38.00 | 3.2 x 2.5 x 1.2 | |
7847730 | 1.0 | 4.0 | 5.7 | 14.00 | 4 x 4.5 x 3.5 | |
784778010 | 1.0 | 3.5 | 7.0 | 30.00 | 7.3 x 7.3 x 3.5 |