Diodes Incorporated FZT849TA

Overview

FZT849TA from Diodes Incorporated is a 30V NPN medium-power high-current transistor in SOT223 package, rated for 7A continuous collector current and 20A peak pulse current, with V_CE(SAT) = 35 mV at I_C = 500 mA / I_B = 20 mA, used in automotive power switching and industrial DC-DC converter output stages.

For engineers reviewing the FZT849TA datasheet, FZT849TA pinout, FZT849TA application, or FZT849TA equivalent, key selection criteria include its AEC-Q101 qualification, low R_CE(SAT) of 36 mΩ at 5A, thermal resistance R_θJA = 42 °C/W (52 mm × 52 mm 2 oz Cu), and complementary PNP pairing with FZT949TA.

Technical Context

This NPN bipolar junction transistor operates in linear and switching modes with guaranteed BV_CEO ≥ 30 V and BVCBO ≥ 80 V, supporting robust blocking in 24V automotive systems. Its h_FE = 100–300 across I_C = 10 mA to 7 A enables stable current amplification in base-driven switch configurations.

Designed for high-reliability applications, it features ESD HBM rating of 4 kV and meets J-STD-020 Level 1 moisture sensitivity. Thermal performance is validated under two PCB mounting conditions: 52 mm × 52 mm 2 oz Cu (R_θJA = 42 °C/W) and 25 mm × 25 mm 1 oz Cu (R_θJA = 78 °C/W).

Key Specifications

Pinout & Package

Package: SOT223 - Surface-mount plastic package with exposed collector tab for thermal enhancement and mechanical anchoring; lead-free, RoHS-compliant, halogen-free "Green" construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN2020ZTA and MJD127G, FZT849TA uniquely balances AEC-Q101 compliance, 7A continuous current, SOT223 surface-mount form factor, and 42 °C/W thermal resistance-making it optimal for space-constrained automotive and industrial power stages where qualification and thermal density matter.

Availability

FZT849TA is available at Aetrix Electronics and suitable for automotive body control modules, industrial DC-DC converters, consumer appliance motor drivers, and telecom power supply fan control requiring stable component supply and long-term lifecycle assurance.

Supply support for FZT849TA 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.

FZT849TA belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, engineered for automotive and industrial switching applications demanding robust thermal performance and long-term stability under cyclic stress.

FAQ

What is the maximum allowable junction temperature for FZT849TA?

The FZT849TA has an operating junction temperature range of –55°C to +150°C. Its absolute maximum T_J is +150°C, and sustained operation above this threshold risks permanent degradation. Derating begins at T_A = 25°C using the specified 24 mW/°C linear factor, requiring thermal design that maintains T_J ≤ 150°C under worst-case load and ambient conditions.

Can FZT849TA be used in linear (analog) amplifier configurations?

FZT849TA is primarily optimized for switching applications, but its h_FE = 100–300 and f_T = 100 MHz permit limited linear use in Class-A or AB audio preamplifier stages with careful biasing and thermal management. However, its V_CE(SAT)-focused design and lack of specified linearity parameters (e.g., THD, distortion curves) make it less suitable than purpose-built RF or audio transistors.

Is the exposed collector tab electrically isolated from other pins?

No-the exposed metal tab on the SOT223 package is internally connected to the Collector terminal and is not electrically isolated. It must be treated as a live circuit node and soldered only to a copper area designated for the collector net. Insulating pads or thermal interface materials with dielectric properties are required if mounting to a grounded heatsink.

Does FZT849TA require gate/base drive protection against voltage spikes?

Yes-while the device includes built-in ESD protection (HBM = 4 kV), it lacks integrated base-emitter clamping diodes. In inductive switching applications, a reverse-biased Schottky diode (e.g., BAT54) between base and emitter is recommended to suppress negative voltage spikes during turn-off and prevent reverse-bias breakdown of the BE junction.