Littelfuse SP4021
SP4021 variants from Littelfuse
SP4021 Overview
What changes between part numbers, and what to check before you lock the BOM — TVS Diodes.
SP4021 is a Littelfuse order-code family — not a single orderable MPN. This page lists 2 variants that share the same core device but differ in suffix fields (package, grade, reel/tube, electrical bin, etc.). Pick the exact full part number; substituting within the family without checking the datasheet often causes assembly or spec mismatches.
TVS Diode 5V 600W 25A Unidirectional SMD Other listed variants describe: TVS Diode Bidirectional 5V 600W SMD.
Suffix examples in this family: 01FTG, 01FTG-C. The characters after the base number usually encode package, temperature, or performance grade — compare the variant table column-by-column rather than assuming pin-compatible drops-in.
Example MPNs: SP4021-01FTG, SP4021-01FTG-C.
Key Features
- Lifecycle mix: ActiveConfirm lifecycle on the exact MPN, not just the base number prefix.
- 2 distinct suffix patternsExamples: 01FTG, 01FTG-C. Decode suffix meaning in the ordering notes under the variant table.
Target Applications
- TVS Diodes — design-in and field replacement
- BOM scrub where only the base prefix is known but suffix is TBD
- Second-source checks when the original MPN is constrained
Ordering Variants
Compare 2 SP4021 part numbers by package, electrical parameters, lifecycle, and availability. Use RFQ for stock and lead-time confirmation.
| Part Number | Description | Manufacturer | Lifecycle | RoHS | Availability | Action |
|---|---|---|---|---|---|---|
| SP4021-01FTG | TVS Diode 5V 600W 25A Unidirectional SMD | Littelfuse | Active | Compliant | In Stock | |
| SP4021-01FTG-C | TVS Diode Bidirectional 5V 600W SMD | Littelfuse | Active | Compliant | In Stock |
Ordering Code Differences
How suffixes on SP4021 map to package, grade, and reel options.
SP4021 uses a shared prefix; characters after the prefix encode orderable options. Two lines with the same prefix are not drop-in replacements unless the differing columns match your need.
Suffixes seen here: 01FTG, 01FTG-C.
Full MPN examples: SP4021-01FTG, SP4021-01FTG-C.
Tip: photograph or copy the reel label — reel diameter, QTY per reel, and moisture sensitivity level (MSL) are often suffix-driven and won't show in the schematic.
How to Choose the Right SP4021 TVS Diodes
Match the footprint first
Pull the exact package drawing for your MPN — base-number swaps fail most often at the footprint, not the schematic.
Electrical headroom
Compare voltage and current columns in the variant table. For SP4021, a suffix with lower voltage or current rating will not survive the same circuit without recalculation.
Temp grade letter matters
Commercial (0–70 °C) and industrial (−40–85 °C+) suffixes look similar in the prefix — confirm ambient + self-heating, not just the first page of the datasheet.
Copy the full MPN
Do not BOM only "SP4021" — include the full suffix (e.g. 01FTG, 01FTG-C). RFQ with reel/tube preference and required date code.
Technical Specifications
Core parameters for SP4021 product family
Identity
Variant Parameters
Source SP4021 with Octatronics
Request stock confirmation, lead time, date code, and pricing for all 2 ordering variants from Littelfuse. Our team supports active, EOL, and hard-to-find component sourcing.
- Original manufacturer parts with traceability options
- BOM upload and multi-line RFQ support
- Package, grade, and compliance verification
Frequently Asked Questions
Common technical questions about the SP4021 product family.