BFS28R MOSFET — Specifications & Equivalents

About the BFS28R

The BFS28R is an N-channel MOSFET with a drain–source voltage (V_DS) rating of 20 V, a continuous drain current (I_D) of 0.02 A and an on-resistance (R_DS(on)) of 300 Ω. It can dissipate up to 0.2 W and is rated to a junction temperature of 150 °C. It is supplied in the TO72 package.

At a glance

• Type: N-channel MOSFET
• Max drain–source voltage (V_DS): 20 V
• Max continuous drain current (I_D): 0.02 A
• On-resistance (R_DS(on)): 300 Ω
• Power dissipation (P_D): 0.2 W
• Max junction temperature (T_J): 150 °C
• Package: TO72

Typical applications

With its 20 V drain–source rating the BFS28R sits in the very-low-voltage class of switching MOSFETs, typically found in battery protection and power-path switching, point-of-load converters and logic-level load switching in portable devices.

At 0.02 A it is aimed at small-signal and light-load switching rather than power conversion.

On-resistance of 300 Ω is relatively high, so this part is better suited to low duty-cycle or low-current switching than to continuous high-current conduction.

Choosing a replacement for the BFS28R

A drop-in substitute for the BFS28R must be the same N-channel type and offer a drain–source rating of at least 20 V, a continuous drain current rating of at least 0.02 A and an on-resistance no higher than 300 Ω if efficiency and heat matter.

Mechanically, check the replacement against the TO72 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.

Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.

Frequently asked questions

What is the BFS28R?

The BFS28R is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 20 V drain-source and 0.02 A continuous drain current.

What is the maximum voltage of the BFS28R?

The BFS28R has a maximum drain-source voltage (Vds) of 20 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the BFS28R handle?

It is rated for 0.02 A of continuous drain current, with power dissipation limited to 0.2 W. Real-world capability depends on your heatsinking and ambient temperature.

What is the on-resistance of the BFS28R?

On-resistance (Rds(on)) is 300 Ω. Multiply by the square of your load current to estimate conduction loss.

What package does the BFS28R come in?

It is listed in TO72. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the BFS28R?

No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.