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

Diodes Incorporated ZTX1149ASTOB

Name: ZTX1149ASTOB
Brand: Diodes Incorporated
SKU: ZTX1149ASTOB
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ZTX1149ASTOB

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3, Formed Leads

Datasheet:: ZTX1149ASTOB.pdf

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

Quantity:: RFQ Add To RFQ list

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Inventory:5,318

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Product details

Overview

ZTX1149ASTOB from Diodes Incorporated (formerly Zetex) is a PNP silicon planar medium-power high-gain bipolar junction transistor in TO-92 compatible package, rated for -25 V V_CEO, -3 A continuous collector current, and 135 MHz transition frequency, used in linear amplification and switching circuits in industrial power supplies and motor control stages.

For engineers reviewing the ZTX1149ASTOB datasheet, ZTX1149ASTOB pinout, ZTX1149ASTOB application, or ZTX1149ASTOB equivalent, key selection criteria include verified V_CE(sat) ≤ -200 mV at I_C = -3 A / I_B = -70 mA, h_FE ≥ 195 at I_C = -2 A, safe operating area up to 10 A pulsed, thermal resistance profile across -55°C to +200°C, and TO-92 mechanical compatibility with legacy board layouts.

Technical Context

This PNP BJT operates in common-emitter configuration with base-controlled current amplification. Its high DC current gain (h_FE up to 800 at low I_C) and low saturation voltage support efficient switching in medium-power DC-DC converters and relay drivers.

The device features robust breakdown ratings: V_(BR)CBO = -30 V, V_(BR)CEO = -25 V, and V_(BR)EBO = -5 V, enabling reliable operation in negative-rail biasing schemes. Thermal performance is characterized by transient thermal resistance curves down to 0.1 ms pulse width and derating to 0.25 W at +120°C ambient.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-25 V - Maximum allowable collector-emitter voltage before avalanche breakdown under open-base condition
I_C (cont.)	-3 A - Continuous collector current rating defining steady-state power handling capability
V_CE(sat)	-200 mV @ I_C = -3 A, I_B = -70 mA - Low saturation voltage minimizes conduction loss in switching applications
h_FE	195 @ I_C = -2 A, V_CE = -2 V - Confirmed DC current gain supporting stable bias design at medium load
f_T	135 MHz @ I_C = -50 mA, V_CE = -10 V - Transition frequency indicating usable bandwidth for RF or fast-switching use cases
T_j Range	-55°C to +200°C - Junction temperature range enabling deployment in automotive under-hood and industrial motor drive environments
P_tot	1 W @ T_amb = 25°C - Total power dissipation limit determining heatsinking requirements

Pinout & Package

Package: TO-92 compatible molded plastic case with E-line lead form (Emitter-Base-Collector pin order when viewed from flat side with leads down).

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current exit terminal for PNP device	Connected to most positive rail in common-emitter switch; sets reference for base bias network
B (Base)	Control electrode for minority-carrier injection	Receives negative-going drive signal; requires current-limited sourcing to avoid overdrive
C (Collector)	Current entry terminal for PNP device	Connected to load and negative supply; carries full switched current and must be routed with low-inductance path

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 195 at I_C = -2 A supports single-stage amplification without cascading
Low V_CE(sat)	-200 mV at full rated current reduces power loss and thermal stress in switching mode
Robust SOA	Rated for 10 A pulsed current with defined safe operating area curves up to 100 ms
Wide temperature range	Operates reliably from -55°C to +200°C junction temperature, suitable for harsh-environment designs
TO-92 compatibility	Drop-in replacement for legacy PNP transistors in existing through-hole PCB footprints

Applications

Industrial Power Supply Control

DC Motor Direction Switching

Use Scenario: Regulating auxiliary bias rails and driving gate-control logic in offline SMPS units.

IC Role / Device Role / Timing Role: PNP switch controlling optocoupler LED current and feedback path enable/disable.

Use Value: Low V_CE(sat) ensures <150 mW dissipation at 3 A, reducing need for heatsinking in compact enclosures.

Use Scenario: Reversing polarity of small DC motors in factory automation actuators.

IC Role / Device Role / Timing Role: High-current PNP emitter-follower stage in H-bridge half-bridge leg.

Use Value: Verified 10 A pulse rating allows brief torque surge handling during motor startup without failure.

Relay Driver Circuit

Linear Current Sink for LED Arrays

Use Scenario: Driving 12 V/24 V electromagnetic relays in programmable logic controllers.

IC Role / Device Role / Timing Role: Saturated PNP switch interfacing microcontroller GPIO to relay coil.

Use Value: h_FE ≥ 195 at -2 A enables direct drive from 5 V MCU outputs with minimal base resistor sizing.

Use Scenario: Precision constant-current sink for high-brightness LED strings in signage systems.

IC Role / Device Role / Timing Role: Linear-mode PNP current regulator with feedback-controlled base bias.

Use Value: Tight V_BE(on) tolerance (-800 to -900 mV) ensures ±3% current accuracy across production lots.

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
ZTX1150ASTOB	V_CEO = -30 V, I_C = -2 A, h_FE = 150 min @ -1 A - higher voltage rating but lower current and gain	Better suited for higher-voltage, lower-current bias networks where V_CEO margin is critical	Select when system V_CC exceeds -22 V and peak current stays below 2 A
MJD2955T4G	TO-220 package, I_C = -12 A, V_CEO = -60 V, h_FE = 20–70 - higher power but lower gain and larger footprint	Designed for high-current linear regulators and heavy-duty motor drives requiring heatsink mounting	Choose only when >5 A continuous current or forced-air cooling is required

Compared with ZTX1149ASTOB, ZTX1150ASTOB trades current capability for higher voltage safety margin, while MJD2955T4G sacrifices gain and board space for scalable thermal handling-neither offers drop-in replacement due to package or gain mismatch.

Availability

ZTX1149ASTOB is available at Aetrix Electronics and suitable for industrial power supply control, DC motor direction switching, and relay driver circuits requiring stable component supply with long-term manufacturing continuity.

Supply support for ZTX1149ASTOB 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 portfolio of high-performance discrete semiconductors focused on precision analog and power-efficient switching.

ZTX1149ASTOB belongs to Zetex's legacy medium-power BJT family, engineered specifically for cost-sensitive industrial controls where TO-92 footprint, gain stability, and thermal ruggedness are prioritized over ultra-high speed.

FAQ

What is the maximum safe pulsed collector current for ZTX1149ASTOB?

The absolute maximum pulsed collector current is -10 A, specified under pulse conditions of 300 µs width and ≤2% duty cycle. This rating assumes adequate PCB copper area for heat spreading and ambient temperature ≤25°C. Exceeding these conditions risks second breakdown or permanent degradation of h_FE.

Can ZTX1149ASTOB be used in linear amplifier configurations?

Yes - its h_FE linearity across I_C = -10 mA to -5 A and low V_CE(sat) variation support Class-A and Class-AB amplifier stages. However, thermal design must account for P_tot derating above 25°C ambient, and f_T limits usable bandwidth to ≤10 MHz for stable gain.

Is ZTX1149ASTOB RoHS compliant and halogen-free?

Yes - Diodes Incorporated certifies ZTX1149ASTOB as RoHS-compliant and halogen-free per IEC 61249-2-21. The TO-92 package uses matte tin-plated leads and epoxy molding compound meeting JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), with no exemptions applied.

Does ZTX1149ASTOB have SPICE model support?

Yes - an official PSpice-compatible model is provided by Diodes Incorporated, derived from the original Zetex 1997 revision. It includes accurate Gummel-Poon parameters (BF=520, BR=40, VAF=24.97 V), junction capacitances (CJE=490 pF, CJC=150 pF), and transient thermal behavior for reliable simulation of switching waveforms and thermal runaway analysis.

ZTX1149ASTOB Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: E-Line-3, Formed Leads

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

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)

ZTX1149ASTOB FAQ

1.How can I place an order for ZTX1149ASTOB through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX1149ASTOB 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 ZTX1149ASTOB reliable?

The price and inventory of ZTX1149ASTOB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX1149ASTOB is usually 5 days.

3.What payment methods are accepted for ZTX1149ASTOB?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX1149ASTOB transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX1149ASTOB?

ZTX1149ASTOB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX1149ASTOB 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 ZTX1149ASTOB?

For technical support, including ZTX1149ASTOB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX1149ASTOB requirements.

6.How does Aetrix verify that ZTX1149ASTOB is sourced from the original manufacturer or authorized distributors?

All ZTX1149ASTOB 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 ZTX1149ASTOB meets industry standards.

7.What is the process for return or replacement of ZTX1149ASTOB?

All ZTX1149ASTOB units undergo pre-shipment inspection (PSI). If there is an issue with ZTX1149ASTOB, 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 ZTX1149ASTOB part is unused and in its original packaging.

Return procedure for ZTX1149ASTOB:

1.Submit a request within 90 days.

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

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