Diodes Incorporated ZUMT591TA

Overview

ZUMT591TA from Diodes Incorporated (formerly Zetex) is a PNP silicon planar transistor in SOT323 package, rated for -1 A continuous collector current, -60 V V_CEO, and 500 mW power dissipation, with V_CE(sat) as low as -0.3 V at I_C = -500 mA / I_B = -50 mA; used in compact DC-DC converter switching stages and battery-powered load switches.

For engineers reviewing the ZUMT591TA datasheet, ZUMT591TA pinout, ZUMT591TA application, or ZUMT591TA equivalent, key selection criteria include verified PNP saturation voltage under pulsed 1A loads, h_FE consistency across 1mA–1A I_C range, SOT323 thermal resistance limits, and compatibility with low-voltage base drive in space-constrained portable systems.

Technical Context

This device operates as a medium-power general-purpose PNP bipolar junction transistor optimized for low-V_CE(sat) switching in high-efficiency, low-profile applications. Its h_FE ranges from 100 at I_C = -1 mA to 15 at I_C = -2 A, supporting both linear biasing and saturated switching modes.

The f_T of 150 MHz at I_C = -50 mA / V_CE = -10 V confirms suitability for audio-frequency and low-MHz switching; C_obo = 10 pF at V_CB = -10 V enables stable operation in feedback-controlled regulators without excessive phase shift.

Key Specifications

Pinout & Package

SOT323 package: surface-mount, 3-terminal plastic case with 0.65 mm lead pitch; thermally enhanced for PCB heat spreading via exposed emitter pad (pin 3).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP switching applications.

Compared with DXT591STZ and ZXTN591TA, ZUMT591TA offers identical performance with guaranteed long-term supply, while ZXTN591TA poses obsolescence risk and DXT591STZ requires no schematic or layout changes but may differ in traceability documentation.

Availability

ZUMT591TA is available at Aetrix Electronics and suitable for portable power management, low-voltage load switching, and DC-DC converter driver applications requiring stable component supply and consistent SOT323 thermal performance.

Supply support for ZUMT591TA 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity.

ZUMT591TA belongs to the Zetex high-performance bipolar transistor family, designed specifically for space-constrained, high-efficiency switching in battery-powered and portable electronics.

FAQ

What is the maximum safe operating temperature for ZUMT591TA?

The junction temperature must not exceed +150°C, and storage temperature range is -55°C to +150°C. At ambient temperatures above 25°C, power dissipation must be derated linearly using the specified thermal resistance (R_θJA ≈ 250°C/W for standard SOT323 on 1-in² FR4), limiting usable I_C at elevated temperatures.

Can ZUMT591TA replace a generic PNP transistor like BC807 in existing designs?

ZUMT591TA has higher I_C (-1 A vs. -500 mA), lower V_CE(sat) (-0.3 V vs. -0.7 V), and tighter h_FE distribution than BC807, but shares SOT323 pinout (C-B-E). Layout compatibility is maintained, though base drive may require adjustment due to higher h_FE at low currents.

Is pulse testing required to achieve the published V_CE(sat) value?

Yes - the -0.3 V typical V_CE(sat) is measured under pulsed conditions (300 µs width, ≤2% duty cycle) to avoid self-heating. For DC operation at -500 mA, expect V_CE(sat) ≈ -0.45 V due to thermal effects, requiring appropriate PCB copper area to maintain T_j < 125°C.

Does ZUMT591TA meet RoHS and REACH compliance?

Yes - ZUMT591TA is manufactured in compliance with EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, with lead-free matte tin termination and halogen-free molding compound, as documented in Diodes Inc.'s official material declarations.