CS55N25AKR CR Micro 250V 55A N-Channel MOSFET TO-247

The CR Micro CS55N25AKR is a 250 V 55 A N-channel MOSFET in a TO-247 package, built on the Planar process. On-resistance is 56 mΩ typical and 69 mΩ maximum at a 10 V gate drive; gate charge is 63.6 nC with 3350 pF input capacitance; threshold voltage spans 3 to 5 V.

Key Specifications

Same-Rating Selection Table

4 part numbers share the same 250 / TO-247 / N rating — sorted by rds(on) typ.

Process Technology

Planar — the gate sits flat on the die surface. Lower channel density than trench designs, but a wider safe operating area, stronger avalanche withstand and simpler gate drive. Preferred for high-voltage and rugged industrial loads where robustness outranks on-resistance.

Applications

Telecom and server DC-DC stages, Class-D audio, PoE interfaces, and 48 V motor drive.

Selection Notes

• Rds(on) rises with junction temperature. Size the heatsink against the hot value given in the datasheet, not the 25 °C number in the table above.
• If the gate is driven below 10 V, check the 4.5 V Rds(on) line — parts without that rating are not characterised for logic-level drive.
• For high-frequency stages compare Qg and Ciss against the Rds(on) gain. A part one bin lower in Rds(on) often costs more switching loss than it saves in conduction.
• The body diode recovery of low-Rds(on) parts can be severe in bridge topologies. Verify dv/dt and dead time against the datasheet before dropping it into a half bridge.

Common Questions

Is the CS55N25AKR an N-channel or P-channel device?

It is N-channel. The drain-source rating is 250 V.

Can the CS55N25AKR be driven at 4.5 V?

No 4.5 V on-resistance figure is published for this part. It is characterised at 10 V gate drive, so use a driver that reaches 10 V.

What is the gate threshold voltage of the CS55N25AKR?

VGS(th) is specified between 3 and 5 V. Below the lower figure the part is off; above the upper figure it is fully on at the rated current.

How much gate charge does the CS55N25AKR need?

Qg is 63.6 nC. Size the driver against that figure at your switching frequency, and add the gate loop loss to the total dissipation budget.

What package does the CS55N25AKR come in?

TO-247. Check the datasheet mechanical drawing for lead spacing and thermal pad dimensions before laying out the footprint.

How do I choose between the 4 part numbers in this rating group?

All 4 share the same voltage and package class. Sort by on-resistance first, then check gate charge: the lowest Rds(on) part is not automatically the best choice if the stage switches at high frequency. The table above lists them in ascending Rds(on) order.