Diodes Incorporated ZXTN08400BNS-7

Overview

ZXTN08400BNS from Diodes Incorporated is a dual NPN medium-power transistor in PowerDI3333-8 package, configured with common-collector topology and rated for 400V V_CEO, 0.5A continuous collector current, and V_CE(SAT) < 175mV at 500mA. It supports high-voltage start-up switching and DC-DC converter primary-side switching where robust blocking and low saturation loss are required.

For engineers reviewing the ZXTN08400BNS datasheet, ZXTN08400BNS pinout, ZXTN08400BNS application, or ZXTN08400BNS equivalent, key selection criteria include its 450V V_CBO, dual-transistor Darlington-configurable architecture, thermal resistance of 68°C/W (with enhanced PCB layout), and compliance with RoHS 3, halogen-free, and antimony-free "Green" standards.

Technical Context

This device integrates two discrete NPN transistors sharing a common collector terminal, enabling configurable operation as independent switches or as a Darlington pair via external base-emitter interconnection. Its 450V V_CBO and 400V V_CEO support high-voltage flyback and offline SMPS applications.

The PowerDI3333-8 package provides low thermal resistance (R_θJL = 19°C/W) and 0.072g mass, with tie-bars internally connected to the common collector-eliminating need for external tie-bar routing while maintaining isolation between emitter-base paths.

Key Specifications

Pinout & Package

Package: PowerDI3333-8 (Type UXB), surface-mount, 8-terminal molded plastic case with matte tin-plated leads, UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage dual-NPN switching applications.

Compared with ZXTN2010ZTA and BCX56-16, ZXTN08400BNS uniquely combines dual-NPN integration, 400V+ blocking, and PowerDI3333-8 thermal performance-enabling compact, high-reliability high-voltage switching without sacrificing current capability or manufacturability.

Availability

ZXTN08400BNS is available at Aetrix Electronics and suitable for high-voltage start-up circuits, offline flyback primary switches, and DC-DC converter enable stages requiring stable component supply, long-term lifecycle assurance, and RoHS 3-compliant sourcing.

Supply support for ZXTN08400BNS 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 consumer markets.

ZXTN08400BNS belongs to Diodes' Power Transistor product line, engineered specifically for high-voltage switching in offline power supplies and industrial control systems where robustness, thermal efficiency, and environmental compliance are mandatory.

FAQ

Can ZXTN08400BNS be used as a direct replacement for a single NPN transistor?

Yes, but only one half of the dual transistor should be used-connect G1/S1 as base/emitter and D as collector, leaving G2/S2 unconnected and floating. The unused transistor does not affect performance, though thermal coupling may slightly improve heat spreading. Do not short unused terminals to ground or V_CC.

What is the maximum allowable base current for reliable operation?

The absolute maximum base current is 0.2A per transistor (IB = 0.2A), but typical design uses IB ≤ 100mA to achieve V_CE(SAT) ≤ 175mV at I_C = 500mA. Exceeding 100mA offers diminishing saturation improvement and risks localized heating at the bond wire interface.

Is the tie-bar electrically connected to any internal node besides the common collector?

Yes-the tie-bars are internally connected exclusively to the common collector (D pin). They are not connected to bases or emitters, and no external connection is required. This design simplifies PCB layout while maintaining electrical isolation between the two transistor sections.

How does thermal performance change when operating at 100°C ambient temperature?

At T_A = 100°C, the maximum allowable power dissipation drops to 0.41W (based on R_θJA = 150°C/W derating), limiting continuous I_C to ~290mA at V_CE(SAT) = 175mV. For sustained 500mA operation above 70°C ambient, use the enhanced layout (R_θJA = 68°C/W) with thermal vias and copper pour.