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

Diodes Incorporated ZTX849

Name: ZTX849
Brand: Diodes Incorporated
SKU: ZTX849
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ZTX849

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3

Datasheet:: ZTX849.pdf

Description:: TRANS NPN 30V 5A E-LINE

Quantity:: RFQ Add To RFQ list

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Inventory:28

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Product details

Overview

ZTX849 from Diodes Incorporated is an NPN silicon planar medium-power high-current transistor rated for 5 A continuous collector current, 30 V V_CEO, and 1.2 W power dissipation at 25°C ambient; it features low V_CE(sat) (≤220 mV at 5 A/200 mA drive) and operates from −55°C to +200°C, used in LCD backlight converters and battery-powered motor drivers.

For engineers reviewing the ZTX849 datasheet, ZTX849 pinout, ZTX849 application, or ZTX849 equivalent, key selection criteria include verified h_FE ≥100 at 5 A, V_CE(sat) performance under pulsed 20 A peak load, thermal resistance R_th(j-amb) = 150°C/W on standard PCB mounting, and TO-92 compatibility for legacy board reuse.

Technical Context

The ZTX849 is a medium-power bipolar junction transistor optimized for switching applications requiring high DC current gain stability across 10 mA–5 A, with h_FE maintained at ≥100 up to 5 A (IC=5 A, V_CE=1 V). Its low saturation voltage enables efficient operation in pulse-driven converters where conduction loss must be minimized.

It supports fast switching with t_on = 45 ns and t_off = 630 ns under defined test conditions (IC = 1 A, IB1/IB2 = 100 mA, V_CC = 10 V), and exhibits f_T = 100 MHz at IC = 100 mA, V_CE = 10 V - confirming suitability for high-frequency switching up to several tens of MHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	30 V - maximum safe collector-emitter voltage before breakdown under open-base condition; defines upper rail limit in switch-mode topologies
I_C (continuous)	5 A - sustained DC collector current capability without thermal runaway on standard PCB mount
V_CE(sat) @ 5 A	220 mV max - ensures ≤1.1 W conduction loss at full load, critical for thermal budget in compact converters
h_FE @ 5 A	100 min - guarantees reliable base drive margin and stable switching behavior under high-current saturation
R_th(j-amb)	150 °C/W - thermal resistance from junction to ambient on 1-inch² copper PCB; determines required heatsinking for 1.2 W dissipation
f_T	100 MHz - usable bandwidth for high-speed switching control loops and RF-coupled driver stages
t_off	630 ns - off-time limiting factor for PWM frequencies above ~500 kHz in synchronous buck or flyback designs

Pinout & Package

Package: TO-92 (E-Line compatible), through-hole, 3-pin plastic case with standard lead spacing and footprint.

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current return path for collector current	Low-impedance reference node; connects directly to ground plane or low-side shunt in switching circuits
B (Base)	Control input for bipolar current amplification	Requires precise current-limited drive (e.g., 200 mA for 5 A I_C) to ensure full saturation and minimize storage time
C (Collector)	Main current output terminal	Connected to switched rail or inductive load; must withstand 30 V transient spikes and handle 5 A RMS current

Key Features

Feature	Design Value
High continuous current rating	5 A I_C - enables single-transistor solutions in 5–10 W DC-DC stages without paralleling
Low V_CE(sat) at high current	220 mV max @ 5 A - reduces conduction loss by >40% vs. typical general-purpose transistors at same current
Wide operating temperature range	−55°C to +200°C - supports under-hood automotive modules and industrial motor controllers without derating
Fast switching speed	t_off = 630 ns - allows use in 500 kHz–1 MHz PWM converters with minimal dead-time penalty
TO-92 mechanical compatibility	E-Line 3-291 footprint - permits drop-in replacement in existing designs using legacy TO-92 layouts

Applications

LCD Backlight Converter

Flash Gun Converter

Use Scenario: Step-up DC-DC converter driving CCFL or LED strings in portable displays.

IC Role / Device Role / Timing Role: Main switching transistor in self-oscillating or PWM-controlled flyback topology.

Use Value: Low V_CE(sat) minimizes heat generation in space-constrained display bezels; 5 A rating supports multi-string configurations.

Use Scenario: High-voltage capacitor charging circuit for xenon flash tubes in DSLR accessories.

IC Role / Device Role / Timing Role: Primary switch controlling energy transfer from battery to HV storage capacitor.

Use Value: 20 A peak current capability handles brief surge loads during capacitor charging; fast t_off enables precise flash timing control.

Battery-Powered Motor Driver

Portable Audio Amplifier Output Stage

Use Scenario: H-bridge half-bridge element driving brushed DC motors in cordless tools or robotics.

IC Role / Device Role / Timing Role: Low-side or high-side switch in discrete BJT-based motor control stage.

Use Value: Stable h_FE ≥100 at 5 A ensures predictable base drive requirements; wide T_j range prevents thermal shutdown in intermittent duty cycles.

Use Scenario: Class AB output emitter-follower stage in battery-powered headphone amplifiers.

IC Role / Device Role / Timing Role: Current-boosting output device delivering >100 mA into low-impedance loads.

Use Value: Low V_BE(sat) (930–1050 mV) improves bias stability and reduces crossover distortion; TO-92 form factor eases manual assembly in prototyping.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-current switching transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX851	P_tot = 1.5 W; V_CEO = 60 V; h_FE ≥ 100 @ 1 A only (not guaranteed at 5 A)	Better voltage headroom but lower current gain stability at full load	Select when system requires >30 V rail tolerance and peak current < 3 A
MJD127	TO-220 package; P_tot = 20 W; V_CEO = 100 V; higher thermal mass but larger footprint	Suitable for higher-power (>10 W) motor drives where PCB space allows	Choose when thermal design requires >5 W dissipation or V_CEO > 30 V is mandatory

Compared with ZTX849, ZTX851 trades current-handling consistency for higher voltage rating, while MJD127 offers scalable power handling at the cost of TO-92 compatibility and board-level integration density.

Availability

ZTX849 is available at Aetrix Electronics and suitable for LCD backlight converters, flash gun converters, and battery-powered motor drivers requiring stable component supply across production lifecycles.

Supply support for ZTX849 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 centers across Asia and manufacturing in China, Taiwan, and Malaysia.

The ZTX series targets medium-power discrete switching applications, emphasizing robustness, thermal reliability, and legacy package compatibility for industrial, consumer, and automotive subsystems.

FAQ

What is the maximum safe operating temperature for ZTX849?

The ZTX849 has a specified junction temperature range of −55°C to +200°C. Its absolute maximum storage and operating temperature is +200°C, validated per JEDEC JESD22-A103. Derating begins above 25°C ambient per the published thermal resistance curve, with full 1.2 W rating only at T_amb = 25°C.

Can ZTX849 replace BC337 in high-current applications?

No - BC337 is rated for 0.8 A I_C and 0.625 W P_tot, while ZTX849 handles 5 A and 1.2 W. Substituting ZTX849 for BC337 requires verifying base drive capability (200 mA needed for 5 A), PCB copper area (1 inch² minimum), and layout clearance for higher current paths.

Is ZTX849 suitable for linear regulator pass transistor use?

Not recommended - its SOA curve shows limited safe operating area in linear mode above 10 V V_CE, and thermal resistance (150°C/W) makes sustained >0.5 W dissipation impractical without external heatsinking. It is optimized for switching, not linear regulation.

Does ZTX849 have built-in ESD protection?

No - the ZTX849 is an unprotected bipolar transistor with no integrated ESD structures. Per datasheet Section "Absolute Maximum Ratings", V_EBO = 6 V and V_CBO = 80 V define hard breakdown limits; external TVS or series resistors are required for ESD-prone environments like handheld device assembly lines.

ZTX849 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: E-Line-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 30 V

Vce Saturation (Max) @ Ib, Ic:: 220mV @ 200mA, 5A

Current - Collector Cutoff (Max):: 50nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 1A, 1V

Power - Max:: 1.2 W

Frequency - Transition:: 100MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

ZTX849 FAQ

1.How can I place an order for ZTX849 through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX849 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 ZTX849 reliable?

The price and inventory of ZTX849 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX849 is usually 5 days.

3.What payment methods are accepted for ZTX849?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX849 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX849?

ZTX849 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX849 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 ZTX849?

For technical support, including ZTX849 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX849 requirements.

6.How does Aetrix verify that ZTX849 is sourced from the original manufacturer or authorized distributors?

All ZTX849 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 ZTX849 meets industry standards.

7.What is the process for return or replacement of ZTX849?

All ZTX849 units undergo pre-shipment inspection (PSI). If there is an issue with ZTX849, 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 ZTX849 part is unused and in its original packaging.

Return procedure for ZTX849:

1.Submit a request within 90 days.

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

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