Diodes Incorporated ZXTN2018FTA

Overview

ZXTN2018FTA from Diodes Incorporated is a 60V NPN low-saturation transistor in SOT23 (Type DN) package, designed for high-current switching with V_CE(sat) ≤ 45 mV at 1 A and R_CE(sat) = 25 mΩ. It delivers 5 A continuous collector current, supports 12 A peak pulse, and withstands 140 V forward blocking voltage-enabling robust gate driving of MOSFETs and IGBTs in motor control circuits.

For engineers reviewing the ZXTN2018FTA datasheet, ZXTN2018FTA pinout, ZXTN2018FTA application, or ZXTN2018FTA equivalent, key selection criteria include its ultra-low saturation voltage at high current, thermal performance on 25 mm × 25 mm copper, safe operating area up to 140 V/5 A, and automotive-qualified variant (ZXTN2018FQ) for mission-critical designs.

Technical Context

This NPN bipolar junction transistor operates as a high-efficiency switch in power interface stages, leveraging its 60 V V_CEO, 140 V V_CEV, and 7 V V_EBO to support wide-voltage rail applications. Its h_FE ranges from 15–220 across 0.1–5 A collector currents, enabling stable gain-controlled drive under varying load conditions.

The device achieves thermal resistance R_θJA = 80 °C/W when mounted on 25 mm × 25 mm 2 oz copper, supporting 12.5 W pulsed power dissipation. Its 130 MHz f_T, 33 ns turn-on time, and 668 ns turn-off time confirm suitability for medium-frequency switching up to ~100 kHz in gate driver and relay drive topologies.

Key Specifications

Pinout & Package

Package: SOT23 (Type DN), surface-mount plastic package with matte tin-plated leads, UL 94V-0 rated molding compound, and 0.008 g mass. Moisture sensitivity level 1 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN low-saturation transistor applications.

Compared with ZXTP2027F and DMT3006LPSQ-13, ZXTN2018FTA offers current-controlled switching with predictable gain and no gate charge, making it ideal for legacy 3.3 V/5 V logic-driven loads where MOSFET gate threshold uncertainty or shoot-through risk exists.

Availability

ZXTN2018FTA is available at Aetrix Electronics and suitable for motor drives, relay control circuits, and solenoid actuation modules requiring stable component supply, automotive-grade alternatives (ZXTN2018FQ), and RoHS-compliant green packaging.

Supply support for ZXTN2018FTA 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-reliability power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.

ZXTN2018FTA belongs to Diodes' ZXT series of high-current, low-saturation bipolar transistors-designed specifically for efficient switching in gate drive, relay, and inductive load interfaces where thermal density and voltage robustness are critical.

FAQ

What is the maximum allowable continuous power dissipation for ZXTN2018FTA at 25°C ambient?

The maximum continuous power dissipation is 1.2 W when mounted on 15 mm × 15 mm 2 oz copper (R_θJA = 125 °C/W), rising to 1.56 W on 25 mm × 25 mm copper (R_θJA = 80 °C/W). Derating begins above 25°C at 12.5 mW/°C for the larger pad layout, ensuring safe operation up to +150°C junction temperature.

Can ZXTN2018FTA replace a standard general-purpose NPN transistor like BC817 in high-current applications?

No-ZXTN2018FTA is not a drop-in replacement for BC817. While both are SOT23 NPN transistors, ZXTN2018FTA delivers 5 A continuous current and 45 mV V_CE(sat) at 1 A, whereas BC817 is rated for 500 mA and has V_CE(sat) > 200 mV. Substituting requires redesigning base drive, thermal layout, and SOA margins.

Does ZXTN2018FTA require a base resistor when driven by a 3.3 V microcontroller GPIO?

Yes-a current-limiting base resistor is mandatory. To achieve full saturation at 1 A collector current, ≥100 mA base current is required (h_FE ≥ 10 at I_C = 1 A). With 3.3 V GPIO and ~0.95 V V_BE(sat), a 22 Ω resistor delivers ~109 mA base current, ensuring reliable switching without overdriving the MCU pin.

Is the ZXTN2018FTA pinout compatible with other SOT23 transistors like MMBT3904?

No-the pinout differs. ZXTN2018FTA uses emitter-base-collector (E-B-C) order in SOT23 (Type DN), while MMBT3904 uses emitter-collector-base (E-C-B) in standard SOT23. Physical insertion into the same footprint will reverse polarity and cause circuit failure; layout must follow the 851 marking and official top-view diagram.