40V Schottky Diodes and Rectifiers

Compare nominal 40 V Schottky barrier diodes for low-voltage rectification, power-path designs and component sourcing. The range spans small SMD signal devices, surface-mount rectifiers and axial or larger power packages. Some shared product menus also offer 20 V, 30 V, 45 V, 50–250 V or other diode types. The collection name does not guarantee that every selectable variant is rated 40 V.

Choose by current class and construction

Compact SMD and signal parts: MBR0540/B0540W selections are described as 40 V, 0.5 A with SOD-123 or SOD-323 choices; nearby MBR0520/0530 choices are different voltage grades. SD103AW/SD103AWS and SD103AX listings describe 40 V, 350 mA devices in SOD-123, SOD-323 or SOD-523. BAS40-04 is a SOT-23 diode array, not a two-terminal rectifier; BAT750 SOT-23 selections also need their exact pinout and marking checked. CDBU0340-HF is listed in a compact 0603-style package. Compare the actual device drawing, not just the size nickname.
1 A to 5 A rectifiers: axial 1N5819 listings identify a 40 V, 1 A DO-41 part; 1N5822 listings identify a 40 V, 3 A DO-201AD/DO-27-class part. SMD menus include SS14, SS24, SS34 and SS54, plus B140A/B240A/B340A, SK34 and B540C/MBRS540 in SMA, SMAF, SMB or SMC packages. Current-grade labels and the package in a headline are not a guarantee of interchangeable thermal performance or footprint. Some listings label SS54/1N5824 as 5 A, 40 V while another variant calls 1N5824 5 A, 30 V: verify the exact manufacturer's datasheet rather than resolving this conflict from the shared title.
Higher-current formats: 15SQ040 R-6/axial selections and D30SC4M TO-247/TO-3P listings target different current and assembly needs. SQ045, SQ050 and other SQ-series options are often 45 V or higher, not 40 V. A high-current headline alone does not establish a safe continuous current in your installation.
Other voltages and families: selectable 1N5817/5818, MBR0520/0530, B230A, SB260, SS56/SS510, SR3100/SR3200, SR5100/SR5200 and higher-voltage power parts are not 40 V choices. A mixed SMD menu also includes M1/M4/M7 ordinary silicon rectifiers, RS1M/US1M recovery families and Schottky SS grades; select the actual diode family, not the first phrase in the product title.

How to specify an order

Determine minimum reverse-voltage margin, continuous forward current, surge demand, junction-temperature range and acceptable forward drop or reverse leakage at the real operating point. Verify ratings and derating in the selected manufacturer's datasheet; descriptions with swapped forward/reverse fields or vague “1KV” claims are not validated limits.
Check terminal arrangement and physical outline: SOD-123, SOD-323 and SOD-523 differ; SMA, SMAF, SMB and SMC are distinct; DO-41/DO-201AD axial parts do not fit SMD pads. Check cathode marking, SOT-23 internal connections, pin assignment and recommended land pattern.
For heat-sensitive builds, calculate conduction loss and use the board copper, heatsinking and ambient-temperature assumptions from the selected datasheet. Do not infer suitability for solar or battery protection solely from marketing examples.
Order the exact model and pack size. Many listings offer a single model in 10, 20, 50, 100, 500, 1,000 or 3,000 pieces, not a mixed kit; other menus let you select another voltage or package. Claims such as “original” are not independent proof of authenticity or certification.

Frequently asked questions

Are SS14, SS24, SS34 and SS54 the same 40 V diode?

No. Listings present different nominal current grades and package options. Match the selected part's electrical limits, case and thermal derating to your BOM.

Can I replace a 1N5819 with an SS14?

Not as a direct mechanical swap: 1N5819 is offered as a DO-41 axial part, while SS14 is commonly listed in SMA. Verify electrical behavior and redesign the footprint if needed.

Are all SQ-series options in this collection 40 V?

No. A 15SQ040 option is labeled 40 V, while SQ045, SQ050 and other variants list higher reverse-voltage grades. Choose by the complete selected part number.