Diodes Incorporated BSS123TC

Overview

BSS123 from Diodes Incorporated is an N-channel enhancement-mode MOSFET in SOT23 package, rated for 100 V drain-source voltage, 6.0 Ω R_DS(ON) at V_GS = 10 V, and 0.17 A continuous drain current. It serves as a low-voltage, low-current switching device in gate driver stages and small servo motor control circuits.

For engineers reviewing the BSS123 datasheet, BSS123 pinout, BSS123 application, or BSS123 equivalent, this part is selected for its low gate threshold (0.8–2.0 V), fast switching (t_D(ON) ≤ 8 ns), low input capacitance (C_iss typ. 22 pF), and rugged 100 V rating in compact SOT23 footprint.

Technical Context

This discrete MOSFET uses Diodes Incorporated's high-density trench technology to achieve low on-resistance while maintaining robust avalanche capability and thermal stability across –55°C to +150°C junction temperature range. Its gate threshold voltage shifts predictably with temperature (±0.5 mV/°C), enabling stable biasing in ambient-variable environments.

The device exhibits low leakage (I_DSS ≤ 0.1 µA at V_DS = 100 V, T_A = 25°C) and low diode forward voltage (V_SD = 0.84 V typ. at I_S = 0.34 A), supporting efficient bidirectional conduction in synchronous rectifier or level-shift configurations.

Key Specifications

Pinout & Package

Package: SOT23 - Surface-mount plastic package with matte tin-plated Alloy 42 leadframe, JEDEC-compliant, moisture sensitivity level 1, weight ≈ 0.008 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel low-voltage switching applications.

Compared with DMN2004LK-7 and FDC637ANZ, BSS123 offers tighter V_GS(TH) tolerance (0.8–2.0 V vs. 1.0–2.5 V), lower leakage (<0.1 µA), and smaller SOT23 footprint-making it optimal for ultra-compact, low-leakage, 3.3 V–driven signal switching where absolute minimum R_DS(ON) is secondary to gate drive simplicity.

Availability

BSS123 is available at Aetrix Electronics and suitable for small servo motor control, power MOSFET gate drivers, and low-voltage load switching requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for BSS123 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, specializing in high-efficiency power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The BSS123 belongs to Diodes' trench-MOSFET product line, engineered specifically for low-power, low-voltage switching applications where gate drive simplicity, thermal efficiency, and JEDEC reliability are prioritized over ultra-low R_DS(ON).

FAQ

Is BSS123 suitable for 3.3 V microcontroller GPIO direct drive?

Yes. With a gate threshold voltage range of 0.8–2.0 V and typical R_DS(ON) of 3.2 Ω at V_GS = 4.5 V, the BSS123 fully turns on using standard 3.3 V logic outputs. Its low input capacitance (22 pF) ensures minimal loading on MCU pins and avoids unintended oscillation without external gate resistors in most cases.

What is the maximum continuous drain current at 85°C ambient?

At T_A = 85°C, the maximum continuous drain current is derated to approximately 0.11 A. This is calculated using the 300 mW power dissipation limit and R_DS(ON) increase with temperature (1.4× at 85°C), resulting in ~250 mW allowable dissipation and corresponding I_D = √(P_D/R_DS(ON)) ≈ 0.11 A.

Does BSS123 include integrated ESD protection?

No. The BSS123 does not integrate dedicated ESD protection structures. Its gate oxide is rated for ±20 V continuous gate-source voltage, but transient ESD events exceeding ±2 kV HBM require external protection (e.g., TVS diode or series resistor) in handling-sensitive environments like automated assembly or field-replaceable modules.

Can BSS123 replace BSS138 in existing designs?

Yes, with verification. BSS123 has higher V_DSS (100 V vs. 50 V), lower R_DS(ON) (3.2 Ω vs. 3.5 Ω at 10 V), and similar gate characteristics. However, its higher gate threshold spread (0.8–2.0 V vs. 0.8–1.5 V) may affect turn-on consistency in marginal 2.5 V drive scenarios-confirm timing margins and leakage in final layout.