Diodes Incorporated DZT491-13

Overview

DZT491-13 from Diodes Incorporated is an NPN epitaxial planar silicon transistor in SOT-223 package, rated for 60 V V_CEO, 1 A continuous collector current, and 1 W power dissipation at T_A = 25°C; used in medium-power switching and linear amplification circuits in industrial power supplies and motor drivers.

For engineers reviewing the DZT491-13 datasheet, DZT491-13 pinout, DZT491-13 application, or DZT491-13 equivalent, key selection criteria include V_CEO/I_C derating at elevated ambient temperature, h_FE consistency across 1–2 A, V_CE(SAT) at I_C = 1 A/100 mA base drive, and thermal performance on FR-4 PCB per AP02001 layout.

Technical Context

This NPN bipolar junction transistor employs epitaxial planar die construction for stable gain and low leakage, with complementary PNP DZT591C available. Its SOT-223 package provides enhanced thermal dissipation over SOT-23, supporting sustained 1 A operation when mounted per Diodes' AP02001 pad layout.

Electrical behavior is characterized under pulsed conditions (≤2% duty, 300 µs width) to minimize self-heating effects. Key operating points include V_CE(SAT) ≤ 0.5 V at I_C = 1 A/I_B = 100 mA and h_FE ≥ 80 at I_C = 1 A, enabling reliable saturation in switch-mode applications.

Key Specifications

Pinout & Package

Package: SOT-223 - Surface-mount plastic package with exposed collector tab for thermal conduction; UL 94V-0 rated, moisture sensitivity level 1, lead-free matte tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DZT491-13, MJD44H11T4 offers higher current headroom at the cost of slower switching, while ZTX653 trades thermal performance for compactness-neither matches the balanced 1 A/1 W/SOT-223 thermal-electrical profile of DZT491-13.

Availability

DZT491-13 is available at Aetrix Electronics and suitable for industrial power supplies, DC motor control modules, LED current regulation circuits, and linear regulator pass stages requiring stable component supply and RoHS-compliant manufacturing.

Supply support for DZT491-13 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 centers across Asia and manufacturing in China, Taiwan, and Malaysia.

The DZT491 belongs to Diodes' general-purpose bipolar transistor product line, engineered for cost-effective, thermally robust medium-power switching and amplification in industrial and consumer power electronics.

FAQ

What is the maximum safe operating current for DZT491-13 at 70°C ambient?

At T_A = 70°C, the maximum continuous collector current is 0.75 A. This is derived from the linear derating curve in Figure 1: 1 W power limit reduces to 0.75 W at 70°C, and with V_CE(SAT) ≈ 0.4 V at mid-current, I_C is constrained by P_D = I_C × V_CE(SAT). Full 1 A operation requires active cooling or reduced ambient.

Can DZT491-13 replace a TO-92 transistor like PN2222A in existing designs?

No direct replacement is recommended without layout revision. DZT491-13 uses SOT-223 with an exposed collector tab requiring a dedicated thermal pad, whereas PN2222A is TO-92 with no thermal pad. Electrical parameters differ significantly: V_CEO = 60 V (vs. 40 V), I_C = 1 A (vs. 0.8 A), and h_FE min = 30 (vs. 100). PCB footprint and thermal design must be updated.

Is the DZT491-13 suitable for audio preamplifier applications?

It is not optimized for low-noise audio preamplification. While h_FE and f_T support small-signal gain, the datasheet does not specify noise figure, distortion, or linearity metrics. Its design focus is switching efficiency and thermal robustness-not signal fidelity. For audio, purpose-built low-noise transistors like BC549C or MPSA18 are preferred.

Does the "Green" designation affect solderability or reliability?

No. The "Green" designation refers to Diodes Incorporated's halogen-free, antimony-free molding compound meeting IEC 61249-2-21 standards. Solderability is fully maintained: matte tin plating passes MIL-STD-202 Method 208, and JEDEC J-STD-020C Level 1 moisture sensitivity ensures safe reflow without popcorn cracking or delamination.