Diodes Incorporated BSS84TC

Overview

BSS84 from Diodes Incorporated is a P-channel enhancement-mode MOSFET in SOT23 package, rated for -50V V_DSS, 10Ω R_DS(ON) at V_GS = -5V, and -130mA continuous drain current. It delivers low gate threshold voltage (-0.8 to -2.0V), fast switching, and low input capacitance (C_iss = 24.6–45pF), enabling efficient power management in space-constrained analog and digital interface circuits.

For engineers reviewing the BSS84 datasheet, BSS84 pinout, BSS84 application, or BSS84 equivalent, key selection criteria include verified R_DS(ON) performance at low V_GS, junction temperature derating of power dissipation (300mW @ 25°C, down to ~150mW @ 100°C), JEDEC-qualified reliability, and SOT23 terminal layout compatibility with high-density PCB routing.

Technical Context

This MOSFET operates as a single-polarity load switch with depletion-free channel turn-on controlled by negative gate-source bias. Its -2.0V maximum V_GS(TH) ensures reliable conduction with logic-level control signals (e.g., 3.3V/5V microcontroller I/O), while low C_oss (4.7–25pF) and Crss (2.8–12pF) minimize switching losses in high-frequency duty-cycle applications.

The device uses silicon planar technology with fully lead-free, halogen- and antimony-free construction compliant with RoHS 3 and AEC-Q stress-test definitions. Thermal resistance R_θJA is 417°C/W on standard FR-4 PCB, requiring careful thermal layout when operating near PD = 300mW limit.

Key Specifications

Pinout & Package

Package: SOT23 (Standard), 3-terminal surface-mount plastic package with matte tin finish, UL 94V-0 rating, and moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar P-channel MOSFET switching applications.

Compared with DMG2305UX and Si2301DDS, BSS84 provides the best balance of ultra-low gate charge (0.28nC), moderate R_DS(ON), and JEDEC reliability in cost-sensitive, low-current (<150mA) switching-ideal for battery-backed analog and interface functions where drive strength and thermal headroom are constrained.

Availability

BSS84 is available at Aetrix Electronics and suitable for power-supply load switching, analog signal routing, logic-level interfacing, and reverse-polarity protection requiring stable component supply across industrial, medical, and consumer electronics programs.

Supply support for BSS84 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The BSS84 belongs to Diodes' general-purpose MOSFET product line, engineered for high-reliability, low-cost switching in space-constrained applications where logic-compatible gate drive and robust thermal performance are essential.

FAQ

What is the maximum safe operating voltage for BSS84 in continuous DC applications?

The BSS84 has a guaranteed V_DSS rating of -50V, meaning it can safely block up to 50V DC between drain and source with zero gate voltage. Operation beyond this value risks avalanche breakdown. Derating is recommended for transient conditions; the device is not rated for repetitive avalanche energy handling.

Can BSS84 be used as a high-side switch with a 3.3V microcontroller GPIO?

Yes - its V_GS(TH) range of -0.8V to -2.0V ensures full enhancement when the gate is pulled to ground and the source is at 3.3V, resulting in V_GS ≈ -3.3V. This exceeds the threshold and achieves low R_DS(ON); no level shifter is required for basic on/off control.

How does ambient temperature affect the continuous drain current rating?

The -130mA I_D rating applies only at T_A = +25°C. Above this, current must be reduced linearly per the derating curve: at +85°C ambient, max I_D drops to approximately -75mA due to thermal resistance (R_θJA = 417°C/W) limiting junction temperature to 150°C.

Is BSS84 suitable for automotive applications?

The standard BSS84 is JEDEC-qualified and meets AEC-Q stress-test definitions, but is not officially AEC-Q200 certified. For production automotive use, Diodes offers the BSS84Q variant - identical electrical specs with full AEC-Q200 qualification and extended temperature screening.