R1242S-A-B Buck Converter overview
Description
R1242S-A-B is a 30.00 V sync Buck Converter from with 3.00 A output current. The maximum 30.00 V input voltage can be regulated down into a 0.80 V to 15.00 V output voltage.
It requires are a typical inductor size of 2.20 µH, a typical external component count of 12 and achieves a peak efficiency of 96 %. Further R1242S-A-B characteristics are a adjustable 1000 kHz switching frequency and 1 available package option(s): HSOP-8 .
Parameter overview and features with replacement search
For the R1242S-A-B 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. | 5.00 V | |
V-IN max. | 30.00 V | |
I-OUT? | 3.00 A | |
V-OUT min. | 0.80 V | |
V-OUT max. | 15.00 V | |
V-OUT | adjustable V | |
V-OUT programmable | ![]() |
|
sync/non-sync | sync | |
Frequency typ. | 1000 kHz | |
Frequency | adjustable | |
Frequency selectable | ||
ext.clock sync. | ![]() |
|
Frequency adj./ ext.clock min. | 330 kHz | |
Frequency adj./ ext.clock max | 1000 kHz | |
Softstart | ![]() |
|
Softstart adjustable | ![]() |
|
Tracking | ![]() |
|
PG/Power OK | ![]() |
|
Quiescent current max. | 1200 µA | |
Operating min. | -40 °C | |
Operating max. | 85 °C | |
Junction min. | ||
Junction max. | ||
thermal shutdown typ. | 160 °C | |
Inductor size typ. | 2.20 µH | |
Inductor suggested by Würth Elektronik | ||
Automotive AEC-Q100 | ![]() |
|
Light-Load-Mode | ![]() |
|
Topology | Buck | |
Peak Efficiency | 96 % | |
Component count min. | 12 | |
current limit adjustable | ![]() |
|
Nr.of packages | 1 | |
CSP | ||
SC70 | ||
SOT | ||
MSOP | ||
QFN/DFN | ||
SO/SOIC | ||
SOP | HSOP-8 | |
DIP | ||
TO | ||
DDPAK |
R1242S-A-B Datasheet
Link to the most up-to-date R1242S-A-B datasheet and the product page for EVM, tools and support information.
R1242S-A-B Sample stock and distributor price breaks
R1242S-A-B prices and online available distributors.


Available Distributors with stock: 0
Available Distributors with stock: 3
Mouser Electronics
Product | Stock | Price | Buy | ||||||||||||||||
R1242S001E-E2-FE | 992 |
| Buy Now | ||||||||||||||||
R1242S001B-E2-FE | 45 |
| Buy Now | ||||||||||||||||
R1242S001A-E2-FE | 970 |
| Buy Now |
Rochester Electronics
Product | Stock | Price | Buy | ||||||||||
R1242S001F-E2-FE | 3000 |
| Buy Now |
Chip1Stop
Available Distributors without stock: 3
Arrow Electronics
Digi-Key
Avnet
List of equivalents and alternatives
The following DC/DC Buck Converter are similar to R1242S-A-B. Optional, compare R1242S-A-B 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 R1242S-A-B.
Order Code | Spec | L (µH) | IR (A) | ISAT (A) | RDC (mΩ) | L x W x H (mm) |
74402500072 | 0.7 | 3.0 | 4.0 | 23.50 | 2.8 x 2.8 x 3 | |
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 | |
74404300082 | 0.8 | 3.5 | 3.7 | 14.00 | 4.8 x 4.8 x 3 | |
744062001 | 1.0 | 4.8 | 4.6 | 10.00 | 6.8 x 6.8 x 2.5 | |
7440690010 | 1.0 | 3.6 | 3.8 | 21.00 | 8 x 8 x 1.5 | |
74407000082 | 0.8 | 6.2 | 5.5 | 8.50 | 8 x 8 x 2 | |
744089410068 | 0.7 | 3.4 | 6.5 | 22.10 | 4.8 x 4.8 x 2.1 | |
74408941010 | 1.0 | 3.0 | 5.4 | 29.50 | 4.8 x 4.8 x 2.1 | |
744089420082 | 0.8 | 3.5 | 6.7 | 21.00 | 4.8 x 4.8 x 3.1 | |
744089430082 | 0.8 | 3.4 | 7.1 | 17.00 | 4.8 x 4.8 x 4.1 | |
74408943010 | 1.0 | 3.3 | 6.5 | 19.00 | 4.8 x 4.8 x 4.1 | |
744383230068 | 0.7 | 3.1 | 4.7 | 46.00 | 2.5 x 2 x 1 | |
744383240068 | 0.7 | 3.2 | 5.9 | 45.00 | 2.5 x 2 x 1.2 | |
744383350082 | 0.8 | 3.5 | 7.0 | 30.00 | 3 x 3 x 1.5 | |
744383360068 | 0.7 | 4.5 | 6.2 | 22.00 | 3 x 3 x 2 | |
74438336010 | 1.0 | 4.0 | 5.0 | 26.00 | 3 x 3 x 2 | |
7447730 | 1.0 | 4.0 | 5.7 | 14.00 | 4 x 4.5 x 3.5 | |
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 | |
74479299210 | 1.0 | 3.0 | 5.2 | 38.00 | 3.2 x 2.5 x 1.2 | |
784383230068 | 0.7 | 3.1 | 4.7 | 46.00 | 2.5 x 2 x 1 | |
784383350082 | 0.8 | 3.5 | 7.0 | 30.00 | 3 x 3 x 1.5 | |
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 |