SMD TVS Diodes and Related Surface-Mount Parts
Compare surface-mount transient-voltage-suppression (TVS) diode options for surge protection in different package sizes. This collection contains SMF and SMFJ compact parts, SMAJ in SMA/DO-214AC, SMBJ in SMB/DO-214AA, SMCJ and 1.5SMC in SMC/DO-214AB, and 5.0SMDJ choices. It also includes a few axial P6KE suppressors and unrelated surface-mount LED, rectifier, Schottky and Zener diode listings. Select the actual variant, not the collection name, to determine what you are buying.
Choose the exact family and case
- Compact SMF and SMFJ: listings describe SOD-123FL/SOD-123F style SMF A and CA grades, including low- and higher-numbered voltage options. SMFJ CA listings combine a named grade with 100-, 300- or 3,000-piece choices. Confirm footprint and polarity from the exact part drawing.
- SMAJ: SMA/DO-214AC options include both A and CA suffixes, from 3.3 to 440 grades in an extended selection. Other listings offer 20-, 50-, 100-, 1,000- or 1,800-piece quantities; a long menu does not mean every grade is in one pack. A few supplier option labels are abbreviated or irregular, so confirm the exact full part number before ordering.
- SMBJ: SMB/DO-214AA selections include unidirectional A and bidirectional CA variants, low-voltage choices and grades into the hundreds. Some products offer 20-, 50-, 100- or 500-piece packs, while 20/100-piece variants select quantity for the same SMBJ5.0A-E3/52 designation. Inspect the selected option for the grade and count.
- SMCJ, 1.5SMC and 5.0SMDJ: larger SMC/DO-214AB options appear in A or CA forms with 10-, 20-, 50- or 100-piece variant choices; 5.0SMDJ listings offer 10-piece selections. Do not assume equal land patterns or surge behavior simply because listings use the same voltage numeral.
Match the part to the protection requirement
- Set reverse standoff voltage (VRWM) above the line's normal maximum, then compare breakdown voltage (VBR) and clamping voltage (VC) at the datasheet's specified pulse current. The grade number in a title is not a universal clamp-voltage guarantee.
- Choose A versus CA deliberately. These commonly denote unidirectional versus bidirectional versions in the listed families, but confirm exact manufacturer nomenclature, markings and pin polarity for the chosen part.
- Compare peak pulse current, pulse-power rating, waveform, repetition and temperature derating on the exact datasheet. Seller headlines of 400 W, 600 W, 1,500 W or 5,000 W do not establish a continuous-power rating or identical performance under different waveforms.
- Verify board footprint, package height, leakage and capacitance for the protected circuit. SMA, SMB, SMC and compact SMF outlines are not automatically interchangeable. For signal lines, capacitance may affect data integrity; for power rails, check operating excursions and surge energy.
- Check the selected variant's part number and quantity. The imported option label “Color” or “Resistance” often contains the actual TVS grade, and some listings instead name rectifier, Schottky, Zener or LED parts. Do not treat these as equivalent transient suppressors.
Frequently asked questions
Does an SMAJ20CA fit an SMBJ20CA footprint?
No assumption of fit is safe. SMA and SMB cases differ; verify both mechanical drawings and the exact electrical characteristics before substitution.
Does the 20 in SMAJ20A specify its clamping voltage?
Not by itself. Check VRWM, VBR and VC at the stated test currents and waveform for the actual selected manufacturer's part.
Are A and CA variants equivalent?
No. They commonly denote different suppression directions. Confirm the full designation and whether the protected line calls for uni- or bidirectional behavior.
Is every item here a surface-mount TVS?
No. Some listings are axial TVS parts; others are LEDs, ordinary rectifiers, Schottky diodes or Zener parts. Read the selected variant and product details before ordering.
