Infineon Technologies BSS7728N

Overview

BSS7728N from Infineon Technologies is an N-channel enhancement-mode logic-level SIPMOS™ small-signal MOSFET rated for 60 V V_DS, 5 Ω R_DS(on) at V_GS = 4.5 V, and 0.2 A continuous drain current; it features dv/dt ruggedness up to 6 kV/µs and operates across –55 °C to +150 °C, commonly used in low-power load switching and signal-level interface circuits.

For engineers reviewing the BSS7728N datasheet, BSS7728N pinout, BSS7728N application, or BSS7728N equivalent, key selection considerations include logic-level gate drive compatibility (V_GS(th) = 1.3–2.3 V), thermal resistance (R_thJA = 350 K/W), reverse diode forward voltage (V_SD = 0.84–1.2 V), and pulsed current capability (I_D,puls = 0.8 A).

Technical Context

This discrete MOSFET employs a silicon-based SIPMOS process optimized for fast switching and robust dv/dt immunity. Its logic-level gate threshold (1.3–2.3 V) enables direct drive from 3.3 V or 5 V microcontrollers without level-shifting circuitry.

It integrates a monolithic body diode with t_rr = 11.5–17.5 ns and Q_rr = 2.6–4 nC, supporting moderate-frequency switching in low-current DC-DC and LED driver topologies where reverse recovery behavior impacts efficiency and EMI.

Key Specifications

Pinout & Package

Package: PG-SOT-23 (JEDEC TO-236AB), surface-mount, lead-free, tape-and-reel (3000 pcs/reel). Marking: sSK.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-power logic-level MOSFET applications.

Compared with DMN2004LK-7 and FDN304P, the BSS7728N offers superior dv/dt immunity and tighter V_GS(th) distribution-critical in noisy industrial environments-while maintaining optimal trade-offs between gate drive simplicity, thermal performance, and cost in low-current switching roles.

Availability

BSS7728N is available at Aetrix Electronics and suitable for LED indicator drivers, microcontroller peripheral switches, and low-voltage sensor interfaces requiring stable component supply and long-term industrial availability.

Supply support for BSS7728N includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies AG is a German semiconductor manufacturer specializing in power management, automotive electronics, and industrial control ICs and discrete devices.

The SIPMOS™ small-signal transistor product line targets precision, logic-compatible switching in space-constrained, low-power applications such as portable instrumentation, industrial sensors, and embedded control subsystems.

FAQ

Is BSS7728N suitable for 3.3 V microcontroller GPIO direct drive?

Yes. With a gate threshold voltage range of 1.3–2.3 V and full enhancement at V_GS ≥ 4.5 V, the BSS7728N reliably turns on using standard 3.3 V CMOS outputs. Its low input capacitance (C_iss = 37–56 pF) minimizes GPIO loading, and no external gate resistor is required for typical switching frequencies below 100 kHz.

What is the maximum safe operating temperature for continuous use?

The BSS7728N has a junction temperature limit of +150 °C and storage range of –55 °C to +150 °C. At ambient temperatures up to +70 °C, its continuous drain current is derated to 0.16 A. Thermal design must account for R_thJA = 350 K/W under minimal PCB copper; adding 1 cm² of 2-oz copper pour reduces this to ~120 K/W.

Does BSS7728N include a built-in body diode, and what are its characteristics?

Yes. It integrates a monolithic body diode with forward voltage V_SD = 0.84–1.2 V at I_F = 0.2 A and reverse recovery time t_rr = 11.5–17.5 ns. The diode supports freewheeling in inductive loads and enables simple flyback protection without external components in low-energy switching circuits.

Can BSS7728N replace BSS138 in existing designs?

Not directly. While both are SOT-23 N-channel MOSFETs, BSS138 has higher V_DS (50 V), lower R_DS(on) (~3.5 Ω @ 10 V), and faster switching-but lacks dv/dt rating and logic-level optimization. BSS7728N's 60 V rating and 6 kV/µs immunity make it preferable in electrically noisy environments, though gate drive timing and thermal margins must be revalidated.