Diodes Incorporated ZX5T853ZTA

Overview

ZX5T853ZTA from Zetex Semiconductors is a 100V NPN medium-power bipolar transistor in SOT89 package, designed for high-side switching and DC-DC power management. It delivers 4.5A continuous collector current, 100V BV_CEO, and ultra-low V_CE(SAT) of 30mV at I_C=1A/I_B=100mA-enabling efficient motor drive and SLIC applications.

For engineers reviewing the ZX5T853ZTA datasheet, ZX5T853ZTA pinout, ZX5T853ZTA application, or ZX5T853ZTA equivalent, key selection criteria include saturation voltage at high current, thermal resistance under defined PCB copper area, peak pulse capability, h_FE consistency across 1–5A, and SOT89 mounting compatibility with thermal vias.

Technical Context

This NPN transistor employs 5th-generation low-saturation process technology optimized for linear and switching operation in medium-power analog and power control circuits. Its BVCBO of 200V and BVCEO of 100V support robust overvoltage margin in industrial line-switching environments.

With f_T = 130MHz and switching times t_ON/t_OFF = 41/1010ns (I_C=1A), it supports fast turn-on in PWM-driven loads while maintaining stable h_FE (100–230) across 10mA–5A operating range-critical for predictable base drive sizing.

Key Specifications

Pinout & Package

Package: SOT89 - Surface-mount, single-ended heat-dissipating outline with exposed emitter tab; requires minimum 50mm×50mm 1oz copper pad for rated 2.1W PD.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZX5T853ZTC, the ZX5T853ZTA trades higher thermal resistance for board-level integration; versus MJD122G, it delivers 4× lower saturation voltage and tighter h_FE tolerance-directly improving efficiency and drive predictability in space-constrained designs.

Availability

ZX5T853ZTA is available at Aetrix Electronics and suitable for motor driving, line switching, high-side switches, and subscriber line interface cards requiring stable component supply and consistent SOT89 thermal performance.

Supply support for ZX5T853ZTA 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

Zetex Semiconductors plc (now part of Diodes Incorporated) was a UK-based designer of high-performance analog and power semiconductors, focused on innovation in bipolar, MOSFET, and precision analog devices.

The ZX5T series targets medium-power discrete switching applications where low saturation voltage, high breakdown rating, and SOT89 thermal reliability are critical-especially in telecom, industrial control, and power conversion.

FAQ

What is the maximum allowable junction temperature for ZX5T853ZTA?

The absolute maximum junction temperature is +150°C, as specified in the thermal characteristics table. Operation above this limit risks permanent degradation of h_FE and increased leakage. Derating begins at T_A = 25°C using the 16.8 mW/°C linear factor for the 50mm×50mm PCB condition, ensuring T_J stays within spec across ambient ranges.

Can ZX5T853ZTA be used in avalanche mode?

No-this device is not rated or characterized for controlled avalanche operation. Its BVCER = 200V is measured with R_B = 1kΩ, indicating standard forward-biased breakdown behavior. Intentional operation beyond BV_CEO = 100V may cause irreversible damage due to localized thermal runaway in the SOT89 structure.

Is the emitter tab electrically isolated from the PCB copper pour?

No-the emitter (Pin 1) is directly connected to the exposed metal tab. When mounted, the tab becomes part of the emitter circuit and must be routed accordingly. This design provides the primary thermal conduction path but requires careful layout to avoid shorting to adjacent ground or supply planes.

How does h_FE variation affect base drive design at 5A load?

At I_C = 5A, h_FE ranges from 10 to 20 per datasheet. To guarantee saturation, base current must be sized for h_FE = 10, requiring ≥500mA drive. The 1.1V V_BE(SAT) confirms that a 5V logic driver with ≤10Ω series resistance meets this-no active current source needed.