Diodes Incorporated DXT3904-13

Overview

DXT3904-13 from Diodes Incorporated is a 40V NPN small-signal transistor in SOT89 package, rated for 200mA continuous collector current and 0.75W power dissipation at 25°C ambient, with DC current gain (h_FE) ranging from 40 to 300 across 100µA–100mA bias conditions, and qualified to AEC-Q101 for automotive-grade reliability in medium-power switching and amplification circuits.

For engineers reviewing the DXT3904-13 datasheet, DXT3904-13 pinout, DXT3904-13 application, or DXT3904-13 equivalent, key selection criteria include V_CEO = 40V, I_C = 200mA, h_FE variation vs. current, thermal resistance (R_θJA = 166°C/W on minimal PCB), and SOT89 mechanical compatibility with high-reliability board-level mounting.

Technical Context

This NPN bipolar junction transistor uses epitaxial planar die construction to deliver stable gain and low saturation voltage across -55°C to +150°C operating range. Its 60V V_CBO, 6V V_EBO, and 4kV HBM ESD rating support robust operation in noisy industrial and automotive environments.

The device exhibits f_T = 300MHz at V_CE = 20V and I_C = 10mA, with typical V_CE(SAT) ≤ 0.20V at I_C = 10mA/I_B = 1mA and ≤ 0.30V at I_C = 50mA/I_B = 5mA - enabling efficient low-voltage switching in discrete driver stages.

Key Specifications

Pinout & Package

Package: SOT89 - surface-mount plastic package with exposed collector pad for enhanced thermal conduction; 3-pin configuration with standardized footprint per AP02002.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN small-signal transistor applications.

Compared with ZXTN25040DFH and MMBT3904-7-F, DXT3904-13 uniquely balances AEC-Q101 compliance, 0.75W dissipation in SOT89, and 40V V_CEO - making it optimal for automotive body electronics needing thermal headroom without over-spec'ing voltage rating.

Availability

DXT3904-13 is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor signal conditioning, and DC-DC converter feedback driver applications requiring stable component supply and AEC-Q101 traceability.

Supply support for DXT3904-13 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, manufacturing, and sales operations across Asia, Europe, and North America.

The DXT3904 belongs to Diodes' AEC-Q101-qualified small-signal transistor product line, engineered specifically for automotive and industrial applications demanding high reliability, thermal robustness, and environmental compliance.

FAQ

What is the maximum allowable collector-emitter voltage for DXT3904-13?

The absolute maximum V_CEO is 40V at T_A = +25°C, verified per DS31141 Rev. 4-2. Operation above this voltage risks avalanche breakdown and permanent damage, even with current limiting. Derating is required above 25°C ambient per the datasheet's thermal curves.

Is DXT3904-13 suitable for linear amplification applications?

Yes - its h_FE of 100–300 at I_C = 1–10mA and low noise figure (NF ≤ 5.0dB at 1kHz) support Class-A and Class-AB small-signal amplification. Stable biasing requires attention to V_BE(ON) variation (0.65–0.95V) and thermal drift across -55°C to +150°C.

How does the SOT89 package affect thermal performance?

The SOT89's exposed collector pad provides direct thermal path to PCB copper. With 1oz copper on a single-sided FR4 board, R_θJA is 166°C/W; increasing copper area to 25mm × 25mm reduces it to 104°C/W - directly enabling higher sustained power dissipation without heatsinks.

Can DXT3904-13 replace DXT3906 in a circuit?

No - DXT3906 is the complementary PNP type, with opposite polarity, different gain profile, and inverted pinout (Emitter/Base/Collector vs. Emitter/Base/Collector mirrored). Direct substitution would reverse biasing and cause circuit failure; use only as matched pair in push-pull or differential topologies.