SMT current transformer selection comparison: VOOHU WHPT-EF126 series replaces TDK B82801C series

1. Product introduction of friendly merchants (TDK Electronics)

TDK B82801C is a SMT current transformer series for switching power supply current detection and feedback loops, providing four-speed transformation ratios of 1:50, 1:100, 1:150 and 1:200. For designs that have adopted this series, the transformation ratio, minimum secondary inductance and 40 A current level should be locked first when selecting, rather than just judging by the appearance of the device.

2. Introduction to VOOHU alternative products (Suzhou VOOHU Electronic Technology Co., Ltd.)

The VOOHU WHPT-EF126 series also covers four levels of electrical specifications and can be evaluated as replacements one by one with the four material numbers of TDK B82801C. The primary side is 11-12 and the secondary side is 2-4, which facilitates comparison among similar current sampling circuits; however, it is not a direct replacement without verification. The existing PCB should also confirm the pad, installation height, gap and actual sampling results.

3. Comparison of core parameters

The key electrical gears of the four models can be matched one by one. The items in the table help complete basic gear matching first; PCB installation, temperature rise and sampling circuits should still be judged based on actual application boundaries.

Note:

1. The four grades of material numbers must match one-to-one: 1:50 corresponds to WHPT-EF126-003, 1:100 corresponds to WHPT-EF126-004, 1:150 corresponds to WHPT-EF126-005, and 1:200 corresponds to WHPT-EF126-006.
2. Both list a 1500 VAC withstand voltage rating, but TDK also gives 50 Hz, 2 s test conditions. Safety verification should be based on project requirements and final sample results.
3. The two series have different maximum dimensions and recommended PCB pad layout. The same terminal definition does not mean that the board can be installed directly without modifying the board. The stock board should check the pad position, installation height, surrounding prohibited area and insulation distance.
4. TDK has special instructions on the temperature rise under the 40 A working condition, which cannot be directly used as a temperature rise commitment for WHPT-EF126. For designs with strict thermal margin requirements, the temperature rise should be confirmed on the target board and actual current waveforms.
5. In high duty cycle or high sampling voltage applications, the volt-second product and sampling load resistance should be re-confirmed based on the controller input range, maximum peak current and actual duty cycle. Recommended values ​​from other part numbers cannot be used directly.

4. Applicable scenarios

1. Current feedback and current sensing loops for switching power supplies, DC/DC and AC/DC power supplies.
2. Power control circuits requiring overcurrent detection, overload protection, load abnormality detection or shutdown protection.
3. Selection of 1:50, 1:100, 1:150 or 1:200 ratio SMT current transformers required for new projects.
4. The original design uses the TDK B82801C series, and plans to add VOOHU supply options after completing PCB and prototype verification.

5. Frequently Asked Questions (FAQ)

Q1: Can the WHPT-EF126 series directly replace the TDK B82801C without changing the PCB?

No such tacit commitment can be made. The primary and secondary side terminal definitions of the two are consistent, but the maximum overall dimensions and recommended pad layout are different. If you have existing boards, you should first confirm the pads, installation height, clearance and assembly conditions before deciding whether to import them.

Q2: How to correspond to the original TDK material number?

B82801C0145A050 corresponds to WHPT-EF126-003; B82801C0565A100 corresponds to WHPT-EF126-004; B82801C1265A150 corresponds to WHPT-EF126-005; B82801C2245A200 corresponds WHPT-EF126-006.

Q3: Can 40 A be directly understood as the same temperature rise performance?

cannot. 40 A is the common current level for both series, but the final temperature rise will be affected by the PCB copper foil, ambient temperature, ventilation conditions and current waveform. For high temperature or continuous high current conditions, it is recommended to use the actual measurement results of the target board as the basis for import.

Q4: What information is more helpful to prepare when applying for samples or technology selection?

It is recommended to provide the original part number, switching frequency, primary side peak or RMS current, controller sampling input range, load resistance, PCB pad or 3D assembly space requirements. This allows for a quicker determination of suitability for the current design.

WHY CHOOSE VOOHU?

One-stop purchasing:Covering connectors + magnetic components + interface chips, full support from selection to small batches.

Customized on demand:Just provide application requirements and budget, and you can get customized solutions and professional technical support.

Rapid R&D:Direct sales from the original factory, fast FAE response, efficient samples, and shortened product launch cycle.

Core qualifications:ISO9001, ISO14001, RoHS, REACH, two self-owned factories guarantee delivery time and quality.

For more inquiries, please visit VOOHU official website:China www.voohu.cn - Overseas www.voohuele.com - Technical support email: voohu@voohu.cn