Diodes Incorporated DXTA42-13

Overview

DXTA42-13 from Diodes Incorporated is an NPN epitaxial planar transistor in SOT89-3L package, rated for 300 V V_CEO, 500 mA I_C, and 1 W power dissipation at T_A = 25°C, with h_FE = 25–40 (I_C = 1–30 mA), used in medium-power switching and linear amplification stages of industrial power supplies and motor control interfaces.

For engineers reviewing the DXTA42-13 datasheet, DXTA42-13 pinout, DXTA42-13 application, or DXTA42-13 equivalent, key selection criteria include V_CEO/V_CBO rating margin, saturation voltage under 20 mA drive, thermal resistance (125°C/W), h_FE consistency across operating current range, and RoHS-compliant lead-free plating compatibility with automated reflow assembly.

Technical Context

This NPN bipolar junction transistor employs epitaxial planar die construction to ensure stable breakdown characteristics and low leakage (ICBO ≤ 0.1 μA at V_CB = 200 V). Its high V_CEO and V_CBO ratings (300 V) support operation in flyback snubber circuits and relay driver stages where transient voltage suppression is critical.

The device delivers V_CE(SAT) ≤ 0.5 V at I_C = 20 mA / I_B = 2 mA and f_T = 50 MHz at I_C = 10 mA / V_CE = 20 V, enabling use in both DC switching and moderate-frequency amplification up to several megahertz without significant gain roll-off.

Key Specifications

Pinout & Package

Package: SOT89-3L - surface-mount plastic case with exposed collector tab for thermal conduction; dimensions per Diodes Inc. outline drawing (D = 4.50 mm, E = 2.50 mm, H = 4.10 mm); UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN medium-power switching applications.

Compared with DXTA42-13, MJD44H11T4 offers higher voltage/current headroom at cost of board space and thermal design complexity, while ZTX653 trades 50 V V_CEO margin for superior gain and current capacity in the same SOT89-3L footprint - making it suitable only where system-level overvoltage protection is externally implemented.

Availability

DXTA42-13 is available at Aetrix Electronics and suitable for industrial power supply auxiliary rails, DC motor direction control circuits, LED string current regulation, and relay driver interfaces requiring stable component supply with consistent parametric performance across production batches.

Supply support for DXTA42-13 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 and manufacturing operations across Asia and the Americas.

The DXTA42 belongs to Diodes' high-voltage NPN transistor product line, engineered specifically for medium-power switching and amplification in industrial and automotive auxiliary systems where reliability under voltage stress and thermal cycling is essential.

FAQ

What is the maximum safe operating collector current for DXTA42-13 at 70°C ambient?

At T_A = 70°C, derated power dissipation is 0.6 W (using R_θJA = 125°C/W and T_J(max) = 150°C). With V_CE(SAT) ≈ 0.45 V at I_C = 300 mA, power loss is ~0.135 W - well within limit. Thus, 500 mA remains permissible if PCB thermal design maintains junction temperature ≤150°C.

Can DXTA42-13 be used in linear amplifier configurations?

Yes - its f_T = 50 MHz and h_FE stability across 1–30 mA support Class-A audio preamplifier and sensor signal conditioning applications. However, thermal design must accommodate continuous power dissipation; recommended bias point is I_C = 5–10 mA with emitter degeneration for linearity.

Is the exposed collector tab electrically isolated from other pins?

No - the metal tab (Pin 1) is internally connected to the collector terminal. It must be treated as a live high-voltage node and routed with appropriate creepage/clearance distances. When soldered to a thermal pad, that pad becomes part of the collector net and must be insulated from adjacent circuitry.

Does DXTA42-13 have a specified avalanche energy rating?

No - the datasheet does not specify single-pulse or repetitive avalanche energy (E_AS). The device is rated for V_CEO = 300 V under DC conditions only. For inductive switching applications, external clamping (e.g., TVS or RCD snubber) is mandatory to prevent secondary breakdown.