Request Quote
(Ships tomorrow)
ELJ-FB121KF Equivalent & Substitute Parts
Part Overview
The ELJ-FB121KF is a 120 µH unshielded wirewound inductor manufactured by Panasonic Electronic Components, rated for 100 mA with a maximum DC resistance of 10Ohm in a 1812 (4532 Metric) surface mount package. This part is classified as obsolete, making equivalent and substitute components necessary for ongoing design support and procurement.
Substitute parts are selected based on matching electrical specifications (inductance value, tolerance, current rating, DC resistance) and mechanical compatibility (package size, mounting type, operating temperature range).
Substiute Parts
Key Parameters
| Parameter | ELJ-FB121KF |
|---|---|
| Inductance | 120 µH |
| Tolerance | ±10% |
| Current Rating | 100 mA |
| DC Resistance (Max) | 10Ohm |
| Shielding | Unshielded |
| Package / Case | 1812 (4532 Metric) |
| Mounting Type | Surface Mount |
| Operating Temperature | -20°C ~ 85°C |
| Product Status | Obsolete |
Substitute Part Grouping Explanation
Substitute parts are organized into two categories based on electrical parameter alignment with the ELJ-FB121KF:
Category 1: Direct Electrical Equivalents (120 µH, ±10%, Unshielded, 1812 Package)
These parts maintain the core electrical specifications of the original part:
- Inductance: 120 µH ±10%
- Package: 1812 (4532 Metric)
- Shielding: Unshielded
- Mounting: Surface Mount
Parts in this category differ in current rating (110 mA vs. 100 mA) and DC resistance (8Ohm vs. 10Ohm), representing improved electrical performance characteristics while maintaining functional compatibility.
Category 2: Enhanced Performance Substitutes (120 µH, ±10%, 1812 Package)
These parts share the same inductance, tolerance, and package but offer higher current ratings or lower DC resistance:
- IMCH1812ER121K: 160 mA rating, 4.5Ohm DCR (wirewound type)
- S1812R-124K: 163 mA rating, 7.5Ohm DCR (shielded variant)
- B82432T1124K000: 180 mA rating, 4.5Ohm DCR (different package variant)
Parameter Comparison
| Part Number | Manufacturer | Inductance | Tolerance | Current Rating (mA) | DCR Max (Ohm) | Shielding | Package | Operating Temp | Product Status | RoHS Status |
|---|---|---|---|---|---|---|---|---|---|---|
| ELJ-FB121KF | Panasonic | 120 µH | ±10% | 100 | 10 | Unshielded | 1812 | -20 to 85°C | Obsolete | - |
| CM453232-121KL | Bourns Inc. | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -40 to 125°C | Active | ROHS3 Compliant |
| IMC1812BN121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | RoHS non-compliant |
| IMC1812EB121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | ROHS3 Compliant |
| IMC1812ER121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | ROHS3 Compliant |
| IMC1812ES121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | ROHS3 Compliant |
| IMC1812RQ121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | RoHS non-compliant |
| IMC1812RV121K | Vishay Dale | 120 µH | ±10% | 110 | 8 | Unshielded | 1812 | -55 to 125°C | Active | RoHS non-compliant |
| IMCH1812ER121K | Vishay Dale | 120 µH | ±10% | 160 | 4.5 | Unshielded | 1812 | -40 to 85°C | Active | ROHS3 Compliant |
| S1812R-124K | API Delevan Inc. | 120 µH | ±10% | 163 | 7.5 | Shielded | 1812 | -55 to 125°C | Active | ROHS3 Compliant |
| B82432T1124K000 | EPCOS - TDK Electronics | 120 µH | ±10% | 180 | 4.5 | Unshielded | 1812 | -55 to 150°C | Active | ROHS3 Compliant |
Engineering Selection Recommendations
Primary Substitutes (Direct Replacement)
CM453232-121KL, IMC1812EB121K, IMC1812ER121K, and IMC1812ES121K are the preferred direct substitutes. All maintain 120 µH inductance, ±10% tolerance, and 1812 package compatibility. These parts offer improved current ratings (110 mA vs. 100 mA) and lower DC resistance (8Ohm vs. 10Ohm), providing enhanced performance margins. CM453232-121KL and the Vishay Dale ROHS3-compliant variants (IMC1812EB121K, IMC1812ER121K, IMC1812ES121K) are recommended for new designs requiring regulatory compliance.
Alternative Substitutes (Enhanced Performance)
IMCH1812ER121K provides 160 mA current rating and 4.5Ohm DCR, suitable for applications requiring lower losses and higher current capacity. S1812R-124K offers shielded construction with 163 mA rating, appropriate for noise-sensitive applications. B82432T1124K000 delivers the highest current rating (180 mA) and lowest DCR (4.5Ohm) with extended temperature range to 150°C, suitable for demanding thermal environments.
Compliance Considerations
For applications requiring RoHS3 compliance, select from: CM453232-121KL, IMC1812EB121K, IMC1812ER121K, IMC1812ES121K, IMCH1812ER121K, S1812R-124K, or B82432T1124K000. IMC1812BN121K, IMC1812RQ121K, and IMC1812RV121K are RoHS non-compliant and should be avoided in regulated applications.
Frequently Asked Questions (FAQ)
Q: Can IMC1812ER121K directly replace ELJ-FB121KF?
A: Yes. Both parts share 120 µH inductance, ±10% tolerance, unshielded construction, and 1812 package. IMC1812ER121K offers improved specifications with 110 mA current rating versus 100 mA, and 8Ohm DCR versus 10Ohm DCR.
Q: What is the difference between IMC1812EB121K and IMC1812ER121K?
A: Both parts are electrically identical (120 µH, 110 mA, 8Ohm DCR, 1812 package). The difference is packaging: IMC1812EB121K is supplied in bulk, while IMC1812ER121K is supplied in tape and reel format. Both are ROHS3 compliant.
Q: Why is S1812R-124K listed as a substitute if it is shielded?
A: S1812R-124K maintains the same inductance value (120 µH), tolerance (±10%), and 1812 package. The shielded construction is an enhancement that reduces electromagnetic interference. It is functionally compatible for applications where shielding is beneficial or neutral.
Q: Can IMCH1812ER121K be used in place of ELJ-FB121KF?
A: IMCH1812ER121K is compatible from an inductance and package perspective (120 µH, 1812 package). However, it offers significantly higher current rating (160 mA vs. 100 mA) and lower DCR (4.5Ohm vs. 10Ohm). Use this part only if the circuit design accommodates these enhanced specifications.
Q: What is the impact of lower DC resistance in substitute parts?
A: Lower DC resistance reduces power dissipation and heat generation in the inductor. Substitutes with 8Ohm or 4.5Ohm DCR (versus 10Ohm) will generate less heat at the same current levels, improving efficiency and thermal performance.
Q: Are all substitute parts available in the same packaging formats?
A: No. CM453232-121KL, IMC1812ER121K, IMC1812ES121K, IMC1812RQ121K, IMC1812RV121K, IMCH1812ER121K, S1812R-124K, and B82432T1124K000 are supplied in tape and reel format. IMC1812BN121K and IMC1812EB121K are supplied in bulk. Verify packaging requirements before procurement.
Q: Which substitute offers the widest operating temperature range?
A: B82432T1124K000 operates from -55°C to 150°C, providing the widest temperature range. This part is suitable for applications in extreme thermal environments.
Alternative Parts
SJ6012L2TP
Littelfuse Inc.
6 Alternative Parts
JMK107BBJ476MA-RE
Taiyo Yuden
10 Alternative Parts
GMK107BBJ475MA-T
Taiyo Yuden
5 Alternative Parts
SJ6020N2ARP
Littelfuse Inc.
3 Alternative Parts
SJ6025R2ATP
Littelfuse Inc.
4 Alternative Parts
2474-05L
API Delevan Inc.
1 Alternative Parts
4590R-684K
API Delevan Inc.
1 Alternative Parts
CM6560R-334
API Delevan Inc.
1 Alternative Parts
CM6460-104
API Delevan Inc.
1 Alternative Parts
5526-12
API Delevan Inc.
1 Alternative Parts