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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

Diodes Incorporated ZTX1149A

Name: ZTX1149A
Brand: Diodes Incorporated
SKU: ZTX1149A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ZTX1149A

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3

Datasheet:: ZTX1149A.pdf

Description:: TRANS PNP 25V 3A E-LINE

Quantity:: RFQ Add To RFQ list

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Product details

Overview

ZTX1149A from Diodes Incorporated (formerly Zetex) is a PNP silicon planar medium-power high-gain bipolar junction transistor rated for -25 V V_CEO, -3 A continuous collector current, and -10 A pulse current, with typical h_FE of 450 at I_C = -10 mA and V_CE = -2 V, used in industrial DC-DC converter switching stages and linear regulator pass elements.

For engineers reviewing the ZTX1149A datasheet, ZTX1149A pinout, ZTX1149A application, or ZTX1149A equivalent, key selection considerations include its TO-92-compatible E-line package, low V_CE(sat) of -140 mV at I_C = -1 A / I_B = -7 mA, thermal resistance profile up to +200 °C junction temperature, and verified safe operating area under pulsed conditions.

Technical Context

This PNP BJT operates in common-emitter configuration with guaranteed breakdown ratings: V_(BR)CBO = -30 V, V_(BR)CEO = -25 V, and V_(BR)EBO = -5 V. Its f_T = 135 MHz at I_C = -50 mA enables use in medium-frequency switching applications.

Switching performance is characterized by t_on = 150 ns and t_off = 270 ns under specified pulsed test conditions (I_C = -4 A, V_CC = -10 V), and its SOA curve supports DC and pulsed operation across ambient temperatures from -55 °C to +125 °C with derating.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-25 V - Maximum allowable collector-emitter voltage before avalanche conduction in open-base condition
I_C (continuous)	-3 A - Continuous DC collector current rating at T_amb = 25 °C with adequate heatsinking
V_CE(sat)	-140 mV @ I_C = -1 A, I_B = -7 mA - Low saturation voltage enabling <1.4 W conduction loss in linear mode
h_FE	450 @ I_C = -10 mA, V_CE = -2 V - High DC current gain supporting low-base-drive requirements
f_T	135 MHz @ I_C = -50 mA, V_CE = -10 V - Transition frequency confirming suitability for sub-150 MHz switching
P_tot	1 W @ T_amb = 25 °C - Total power dissipation limit defining thermal design envelope
t_off	270 ns @ I_C = -4 A, ±I_B = 40 mA - Measured turn-off delay critical for PWM duty cycle fidelity

Pinout & Package

Package: TO-92-compatible E-line molded plastic case with emitter (E), base (B), and collector (C) leads arranged in standard linear order (E-B-C viewed from flat side).

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current source terminal for PNP operation	Connected to higher potential rail; carries full load current in common-emitter switch
B (Base)	Control input for minority-carrier injection	Requires negative bias relative to emitter to forward-bias BE junction and enable conduction
C (Collector)	Current sink terminal	Typically tied to load or ground-return path; voltage swing limited by V_CEO rating

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 450 at low I_C reduces required base drive current and driver-stage complexity
Low saturation voltage	V_CE(sat) ≤ -140 mV at I_C = -1 A minimizes conduction losses in linear and saturated switching modes
Extended temperature range	Junction storage rating up to +200 °C supports operation in high-ambient industrial environments
Pulsed current capability	ICM = -10 A enables short-duration overload handling without secondary breakdown
Verified SOA compliance	Defined safe operating area curves support reliable design across DC, 10 ms, and 100 µs pulse widths

Applications

DC-DC Converter Switch

Linear Regulator Pass Element

Use Scenario: Used as main switching transistor in non-synchronous buck converter output stage operating at 50–200 kHz.

IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter topology, driven by TTL/CMOS-level base control signal.

Use Value: Low V_CE(sat) and high h_FE reduce gate-driver overhead and improve efficiency at 1–3 A load currents.

Use Scenario: Employed as series pass element in adjustable negative-voltage linear regulator delivering -5 V @ 1.5 A.

IC Role / Device Role / Timing Role: Operated in active region with feedback-controlled base bias to regulate output voltage.

Use Value: Stable h_FE over temperature and low V_CE(sat) minimize dropout voltage and thermal drift.

Industrial Motor Driver Stage

Overcurrent Protection Circuit

Use Scenario: Integrated into H-bridge half-bridge leg for 24 V brushed DC motor control in factory automation equipment.

IC Role / Device Role / Timing Role: Acts as high-side PNP switch controlling motor supply connection during PWM commutation.

Use Value: Verified 270 ns t_off ensures clean turn-off during fast PWM transitions, reducing shoot-through risk.

Use Scenario: Configured in current-sensing foldback circuit that disables power stage when load exceeds 3 A threshold.

IC Role / Device Role / Timing Role: Functions as latching comparator output stage triggered by sense-resistor voltage.

Use Value: Guaranteed V_(BR)CEO = -25 V and ICES ≤ -100 nA ensure stable trip point and low false-trigger probability.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD2955	TO-220 package, higher P_tot = 115 W, V_CEO = -70 V, h_FE min = 20 at I_C = -4 A	Designed for higher-power heat-sinked applications; not drop-in compatible due to package and gain profile	Select when >3 A continuous current or forced-air cooling is required
ZTX1051A	Same TO-92 E-line package, V_CEO = -60 V, I_C = -2 A, h_FE = 300 @ I_C = -10 mA	Higher voltage rating but lower current capacity; identical footprint and pinout	Choose for -60 V systems where space-constrained TO-92 mounting is mandatory

Compared with MJD2955 and ZTX1051A, ZTX1149A offers optimal balance of gain, saturation voltage, and thermal capability in the TO-92 form factor-making it preferred for compact, medium-current linear and switching designs where board space and base-drive efficiency are prioritized over ultimate power handling.

Availability

ZTX1149A is available at Aetrix Electronics and suitable for industrial motor drivers, DC-DC converters, and linear regulator circuits requiring stable component supply with long-lifecycle availability and traceable sourcing.

Supply support for ZTX1149A 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 acquired Zetex plc in 2008 and maintains its legacy portfolio of high-performance discrete semiconductors focused on analog and power management solutions.

ZTX1149A belongs to Zetex's medium-power BJT product line, engineered for robust switching and linear regulation in industrial and automotive-qualified power systems where reliability under thermal stress is critical.

FAQ

What is the maximum safe operating temperature for ZTX1149A?

The ZTX1149A has a specified junction and storage temperature range of -55 °C to +200 °C. Its maximum continuous operating temperature is limited by power dissipation and thermal resistance; at T_amb = 25 °C, P_tot = 1 W defines the upper thermal boundary, and derating to zero power occurs at +125 °C ambient per the published curve.

Is ZTX1149A suitable for use in automotive applications?

ZTX1149A is not AEC-Q101 qualified and lacks automotive-specific qualification documentation. While its -55 °C to +200 °C temperature rating meets some under-hood thermal requirements, it is intended for industrial and commercial applications per Diodes Incorporated's product segmentation and reliability testing scope.

Does ZTX1149A have SPICE model support?

Yes-Zetex released an official PSPICE-compatible model for ZTX1149A dated October 1, 1997, including parameters for IS, BF, VAF, IKF, CJE, CJC, TF, and TR. The model is publicly archived and validated for transient and DC analysis in common-emitter configurations.

How does ZTX1149A compare to NPN counterparts like ZTX1050A?

ZTX1149A (PNP) and ZTX1050A (NPN) share the same TO-92 E-line package and complementary voltage/current ratings, but differ in polarity-driven circuit roles: ZTX1149A serves high-side switching and negative-rail regulation, while ZTX1050A is used in low-side switching and positive-rail applications-requiring opposite biasing and layout considerations.

ZTX1149A Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: E-Line-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 25 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 70mA, 3A

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 250 @ 500mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 135MHz

Operating Temperature:: -55°C ~ 200°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: E-Line (TO-92 compatible)

ZTX1149A FAQ

1.How can I place an order for ZTX1149A through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX1149A on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for ZTX1149A reliable?

The price and inventory of ZTX1149A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX1149A is usually 5 days.

3.What payment methods are accepted for ZTX1149A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX1149A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX1149A?

ZTX1149A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX1149A order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for ZTX1149A?

For technical support, including ZTX1149A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX1149A requirements.

6.How does Aetrix verify that ZTX1149A is sourced from the original manufacturer or authorized distributors?

All ZTX1149A products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ZTX1149A meets industry standards.

7.What is the process for return or replacement of ZTX1149A?

All ZTX1149A units undergo pre-shipment inspection (PSI). If there is an issue with ZTX1149A, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The ZTX1149A part is unused and in its original packaging.

Return procedure for ZTX1149A:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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