Diodes Incorporated 2DD2678-13

Overview

2DD2678-13 from Diodes Incorporated is a low V_CE(SAT) NPN bipolar junction transistor in SOT89-3L package, rated for 3 A continuous collector current, 12 V V_CEO, and 90–250 mV saturation voltage at I_C = 1.5 A / I_B = 30 mA. It serves as a medium-power switching device in DC-DC converter output stages and LED driver load switches.

For engineers reviewing the 2DD2678-13 datasheet, 2DD2678-13 pinout, 2DD2678-13 application, or 2DD2678-13 equivalent, key selection criteria include verified V_CE(SAT) performance under pulsed 1.5 A loads, h_FE range of 270–680 at 500 mA, thermal resistance of 62.5 °C/W with 1 in² copper pad, and RoHS-compliant matte tin plating on copper leadframe.

Technical Context

This NPN transistor uses epitaxial planar die construction to achieve stable gain and low saturation voltage across temperature. Its f_T of 170 MHz supports high-speed switching up to ~100 kHz in PWM-driven applications, while C_obo of 26 pF minimizes capacitive loading in gate-drive or feedback paths.

The device operates across –55°C to +150°C junction temperature, with dual power dissipation ratings (0.9 W standard FR-4 layout; 2 W enhanced 1 in² copper pad). Pulse-tested V_(BR)CEO and V_CE(SAT) ensure reliability in transient-heavy industrial switching environments.

Key Specifications

Pinout & Package

Package: SOT89-3L - surface-mount plastic package with exposed emitter tab for thermal conduction; dimensions: 4.5 mm × 2.45 mm × 1.05 mm (L × W × H), weight ≈ 0.072 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN25050DFH and MJD2955T4G, the 2DD2678-13 uniquely balances 3 A capability, 90 mV V_CE(SAT), and SMT-compatible thermal performance-making it optimal for compact, thermally managed 12 V industrial switching where both current and efficiency matter.

Availability

2DD2678-13 is available at Aetrix Electronics and suitable for DC-DC converter output stages, LED constant-current drivers, industrial relay drivers, and power supply enable switches requiring stable component supply and RoHS-compliant manufacturing.

Supply support for 2DD2678-13 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 2DD2678 belongs to Diodes' general-purpose bipolar transistor product line, engineered for cost-sensitive, medium-power switching and amplification in industrial, consumer, and computing power systems.

FAQ

What is the maximum allowable continuous collector current for 2DD2678-13 under standard PCB conditions?

The datasheet specifies 3 A continuous collector current only when mounted on an FR-4 PCB with a 1 in² copper pad layout. With minimum recommended pad layout, the rating drops to 0.9 W power dissipation, limiting I_C to approximately 1.2 A at V_CE(SAT) = 250 mV. Thermal derating curves in Figure 1 must be applied for ambient temperatures above 25°C.

Can 2DD2678-13 be used in linear regulator applications?

Yes-it is qualified for linear operation with V_CEO = 12 V and T_J(max) = +150°C. However, its 2 W max power dissipation (with 1 in² copper) limits usable dropout voltage × load current combinations. For example, at 500 mA load, maximum safe V_IN–V_OUT is 4 V. Always verify junction temperature using R_θJA = 62.5 °C/W and ambient conditions.

Is the emitter tab electrically isolated from the package leads?

No-the exposed metal tab on the SOT89-3L package is internally connected to Pin 2 (Emitter) and must be treated as a live terminal. It cannot serve as a floating thermal pad. PCB layout must assign the tab to the same net as the emitter trace and avoid accidental shorting to ground or adjacent signals.

Does 2DD2678-13 support pulse-width modulation at frequencies above 50 kHz?

Yes-its f_T of 170 MHz and low C_obo (26 pF) allow clean switching up to at least 100 kHz. Measured V_CE(SAT) and h_FE data are provided under 300 μs pulses (≤2% duty cycle), confirming suitability for PWM control. Rise/fall times are not specified, but typical values for similar SOT89 NPNs are <100 ns with 10 kΩ base drive.