Diodes Incorporated FZT591ATC

Overview

FZT591ATC from Diodes Incorporated is a 40V, -1A PNP medium-power transistor in SOT223 package, featuring V_CE(SAT) < -500 mV at -1 A, BV_CEO = -40 V, and h_FE = 300–800 (IC = -1 mA to -1 A). It serves as a high-current gate driver for power MOSFETs and IGBTs in automotive and industrial switching circuits.

For engineers reviewing the FZT591ATC datasheet, FZT591ATC pinout, FZT591ATC application, or FZT591ATC equivalent, key selection criteria include saturation voltage under high collector current, thermal resistance (R_θJA = 62.5 °C/W on 25 mm × 25 mm PCB), AEC-Q101 qualification, and complementary pairing with FZT491A.

Technical Context

This PNP bipolar junction transistor operates in linear or saturated switching mode with guaranteed breakdown ratings up to -40 V (V_CEO, V_CBO) and -7 V (V_EBO). Its h_FE spans 30–800 across IC = -1 mA to -2 A, supporting both low-current biasing and high-current switching.

Thermal design is enabled by dual R_θJA values: 62.5 °C/W (25 mm × 25 mm 2 oz Cu) and 41.7 °C/W (50 mm × 50 mm 2 oz Cu), with R_θJL = 19.4 °C/W confirming efficient heat conduction through the collector lead.

Key Specifications

Pinout & Package

SOT223 (Type DN) surface-mount package with exposed collector tab for thermal enhancement; molded green compound, UL 94V-0 rated, 0.112 g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN25050DFHTA and MJD44H11RLG, FZT591ATC offers optimal balance of AEC-Q101 compliance, SOT223 compactness, and proven -1 A gate-drive performance-making it preferred for space-constrained automotive modules where qualification and thermal efficiency are jointly prioritized.

Availability

FZT591ATC is available at Aetrix Electronics and suitable for automotive gate driving, industrial power switching, complementary push-pull stages, and ESD-robust signal interface applications requiring stable component supply and long-term lifecycle support.

Supply support for FZT591ATC 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, manufacturing, and sales operations across Asia, Europe, and North America.

FZT591ATC belongs to Diodes' high-reliability bipolar transistor product line, engineered specifically for robust gate-driving and power-switching roles in automotive and industrial environments where AEC-Q101 validation and thermal stability are mandatory.

FAQ

Is FZT591ATC pin-compatible with FZT591A?

Yes. FZT591ATC uses the same SOT223 (Type DN) package and identical pin-out (Collector–Emitter–Base) as FZT591A. The "TC" suffix denotes tape-and-reel packaging per Diodes' internal ordering convention and does not affect electrical or mechanical compatibility.

What is the maximum allowable base current for continuous operation?

The absolute maximum base current is -200 mA per datasheet Absolute Maximum Ratings. For reliable continuous operation at I_C = -1 A, base current should be limited to -100 mA (h_FE ≥ 10), ensuring thermal stability and avoiding secondary breakdown under sustained DC conditions.

Can FZT591ATC replace a small-signal PNP like BC807 in gate-drive circuits?

No. While both are PNP transistors, FZT591ATC is rated for -1 A continuous current and 2 W dissipation, whereas BC807 is limited to -500 mA and 310 mW. Substituting BC807 risks thermal runaway and premature failure when driving power devices requiring >100 mA base current.

Does FZT591ATC require a heatsink in typical gate-drive use?

Not typically. With V_CE(SAT) < -500 mV at -1 A, power dissipation stays below 0.5 W in saturated switching. On a 25 mm × 25 mm 2 oz copper PCB, junction temperature rise remains within limits (ΔT = 0.5 W × 62.5 °C/W = 31.25 °C), eliminating need for external heatsinking in most gate-drive implementations.