SRU1028-1R0Y Bourns Inductor (Inductors Precision Moulded) In Stock
Bourns SRU1028-1R0Y is a 1 µH power inductor with an ultra-low 4.9 milliohm DC resistance in a precision-moulded 3939 case ferrite core package. It is a general-purpose power inductor designed for DC-DC converters and power management circuits requiring high current handling and low losses. Available worldwide with RoHS-compliant lead-free construction for demanding power electronics applications.
- Manufacturer
- Bourns
- Package
- Inductors Precision Moulded
- Pin Count
- 2
- Lifecycle
- ACTIVE
- Datasheet
- SRU1028-1R0Y Datasheet PDF
- Category
- Inductor
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 1 µH nominal inductance with ultra-low 4.9 mΩ DC resistance for minimal I²R power loss
- Ferrite core construction in a 3939 case ensures stable inductance under high-current DC bias conditions
- Precision-moulded rectangular package enables repeatable automated SMT assembly
- General-purpose power inductor rated for DC-DC converter and switching regulator applications
Applications
The SRU1028-1R0Y is used as the main power inductor in DC-DC buck and boost converters, synchronous rectifiers, and point-of-load regulators where high efficiency and low DCR are critical. Its 1 µH inductance and ferrite core are well-suited for switching frequencies in the range of 1 MHz to 5 MHz commonly used in modern power management ICs. It is also employed in filtering applications for CPU and GPU power supplies, server VRMs, and automotive power modules where high current and compact size are required.
Specifications
| Pbfree Code | Yes |
| Factory Lead Time | 16Weeks |
| YTEOL | 7.9 |
| Case/Size Code | 3939 |
| Construction | Rectangular |
| Core Material | FERRITE |
| DC Resistance | 0.0049Ω |
| Inductance-Nom (L) | 1 µH |
| Inductor Application | POWER INDUCTOR |
| Inductor Type | GENERAL PURPOSE INDUCTOR |
| JESD-609 Code | e2 |
| Number of Functions | 1 |
| Package Height | 2.8mm |
| Package Length | 10mm |
| Package Style | SMT |
| Package Width | 10mm |
| Packing Method | TR, EMBOSSED, 13 INCH |
| Rated Current-Max | 7A |
| Self Resonance Frequency | 100MHz |
| Shape/Size Description | RECTANGULAR PACKAGE |
| Shielded | YES |
| Surface Mount | YES |
| Terminal Finish | SILVER NICKEL TIN |
| Terminal Placement | DUAL ENDED |
| Terminal Shape | ONE SURFACE |
| Test Frequency | 0.1MHz |
| Tolerance | 30% |
| Package | Inductors Precision Moulded |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8504.50.80.00 |
| Country of Origin | Mainland China |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SRU1028-1R0Y:
suggested
Frequently Asked Questions
How does the 4.9 mΩ DCR of the SRU1028-1R0Y affect efficiency in a 5 A buck converter?
At 5 A of inductor current, the SRU1028-1R0Y's 4.9 mΩ DC resistance dissipates only 0.12 W (P = I² x R = 25 x 0.0049), representing less than 0.5% power loss in a 24 W output converter. This ultra-low DCR makes it suitable for high-efficiency designs targeting above 95% conversion efficiency. By comparison, an inductor with 20 mΩ DCR would dissipate 5x more power, significantly reducing system efficiency.
What switching frequency range is the SRU1028-1R0Y optimized for in a DC-DC converter design?
The SRU1028-1R0Y's 1 µH ferrite core inductor is optimized for switching frequencies between 500 kHz and 5 MHz, where the inductance value balances ripple current amplitude and core losses. At 1 MHz switching frequency with a 12 V input and 5 V output in a buck converter, the 1 µH inductance limits peak-to-peak ripple current to approximately 3.5 A for a duty cycle of 0.42, ensuring continuous conduction mode at loads above 1.75 A.
How does the 3939 case size of the SRU1028-1R0Y help in compact power module designs?
The 3939 case size designates a 10 mm x 10 mm (approximately) footprint, providing a large surface area for heat dissipation while maintaining a low profile suitable for power modules with tight height constraints below 3 mm. This compact form factor allows the SRU1028-1R0Y to be placed close to switching regulator ICs, minimizing parasitic inductance in the power loop and reducing EMI emissions in dense PCB layouts.
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