iEH48025A120V-003-R (TDK-Lambda iEH Series, Isolated DC-DC Power Module, 1/8 Brick)

- Part Number: iEH48025A120V-003-R

- Type: Isolated Step-down DC-DC, 1/8 Brick Through-hole Module

- Nominal Input: 48Vdc, **Input Range: 36～75Vdc**, 100ms transient withstand voltage up to 100Vdc

- Output: 12Vdc, Max. 25A, Rated Power 300W

- Efficiency: Typical 94.6%

- Isolation Voltage: 2250Vdc isolation between input and output

- Ripple & Noise: Typical 85mVpp

- Operating Temperature: -40℃ ~ +124℃ (Baseplate Temperature)

- Dimensions: 58.42 × 22.86 ×12.70 mm, Weight approx. 50g

- Protections: OVP Over Voltage Protection, OCP Over Current Protection, OTP Over Temperature Protection (Latch-off type)

- Safety Certifications: IEC/UL/CSA/EN 62368-1, CE, UKCA

- Environmental Compliance: RoHS compliant

- Construction: Equipped with baseplate for conductive cooling

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> Part Number Breakdown: iEH = iEH Series; 48 = Nominal 48V Input; 025 = Max. Output 25A; A120 = 12V Output; 003 = Baseplate Version; R = Tape & Reel / Factory Revision

✅ Functions

1. Intermediate Bus Converter (IBC): Isolates and steps down the 48V telecom bus to a stable 12V intermediate bus to supply downstream POL (Point-of-Load) power supplies.

2. Electrical Isolation: High voltage isolation between primary 48V side and secondary 12V side, improving system safety and suppressing ground loop noise.

3. Regulated Output: Maintains stable 12V output across wide input voltage range with excellent line and load regulation.

4. Pre-Bias Start-up Supported. No reverse current occurs in multi-module parallel systems, suitable for server and telecom power architectures.

5. Built-in comprehensive protection circuits: OVP, OCP and OTP with latch-off upon fault.

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> Architecture Note: Distributed Power Architecture (DPA). The IBC only performs bus voltage step-down and isolation. Downstream small POL ICs further step down voltage to the low voltage required by CPU / FPGA.

 Application Scope

- Power systems for servers, data centers and storage devices

- Telecom / networking equipment, 48V telecom racks

- Industrial switches, base stations and embedded computing platforms

- **Distributed Power Architecture (DPA) solutions requiring isolated high-power, high-efficiency 48V to 12V conversion**

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> Advantages: Baseplate conductive cooling enables full power output at high ambient temperature. High isolation meets safety requirements for telecom / IT equipment. Pre-bias start-up ensures stable operation under multi-load conditions.

iEH48025A120V-003-R is a TDK-Lambda iEH series 1/8 brick isolated DC-DC module. It converts 48V input to 12V/25A at 300W with typical efficiency of 94.6% and 2250Vdc input-to-output isolation. Featuring a baseplate for conductive cooling and pre-bias start-up capability, it is widely used in distributed power supplies for servers and telecom cabinets as an Intermediate Bus Converter (IBC).