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

Diodes Incorporated ZTX651QSTZ

Name: ZTX651QSTZ
Brand: Diodes Incorporated
SKU: ZTX651QSTZ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ZTX651QSTZ

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3, Formed Leads

Datasheet:: ZTX651QSTZ.pdf

Description:: TRANS NPN 60V 2A E-LINE

Quantity:: RFQ Add To RFQ list

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Inventory:2,195

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Product details

Overview

ZTX651QSTZ from Diodes Incorporated is a 60V NPN medium-power transistor in E-Line (TO-92 compatible) package, rated for 2A continuous collector current, 6A peak pulse current, and 1W power dissipation at +25°C ambient. It features low V_CE(sat) of 230 mV @ 1A/100mA, operates up to +200°C junction temperature, and is AEC-Q101 qualified for automotive applications including engine control modules and body electronics.

For engineers reviewing the ZTX651QSTZ datasheet, ZTX651QSTZ pinout, ZTX651QSTZ application, or ZTX651QSTZ equivalent, key selection criteria include its 60V V_CEO, 2A I_C, thermal robustness to +200°C, AEC-Q101 qualification, and E-Line through-hole mounting compatibility with TO-92 footprint constraints.

Technical Context

This NPN bipolar junction transistor is optimized for medium-power switching in automotive and industrial environments where high-temperature reliability and pulse-current capability are critical. Its 70°C/W junction-to-lead thermal resistance enables efficient heat transfer via the collector lead, and its 140–175 MHz f_T supports fast-switching operation in PWM-driven loads.

The device meets JEDEC HBM ESD rating ≥4 kV and MM ≥400 V, and its 1.5 W maximum power dissipation (with appropriate PCB layout) allows sustained conduction under transient overloads. The 7 V V_EBO and 80 V V_CBO provide margin for inductive flyback and bias network stability.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	60 V - Maximum safe collector-emitter voltage before breakdown in common-emitter configuration
I_C	2 A - Continuous DC collector current sustainable with proper heatsinking and ambient conditions
V_CE(sat)	230 mV @ 1A/100mA - Low saturation voltage ensures minimal conduction loss in switching applications
f_T	140–175 MHz - Current gain-bandwidth product enabling reliable operation in high-speed switching circuits
R_ΘJL	70 °C/W - Junction-to-lead thermal resistance supports direct heat conduction through collector lead
T_J max	+200 °C - Maximum junction temperature rating permits use in under-hood automotive environments
ESD HBM	≥4 kV - Human Body Model rating confirms robustness against handling-induced electrostatic discharge

Pinout & Package

E-Line (TO-92 compatible) molded plastic package with matte tin-plated leads; 0.159 g weight; UL 94V-0 flammability rating; flat-face orientation with emitter-collector-base (E-C-B) pin sequence when viewed from flat side with leads down and marking facing up.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal	Low-impedance return path; connected to ground or low-side reference in switch configurations
Collector (C)	Current source terminal	Primary power-handling node; thermally coupled to PCB via lead for heat extraction
Base (B)	Control input	Drives transistor into saturation or cutoff; requires ~100 mA drive for full 1A switching

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive-grade reliability including temperature cycling, humidity, and mechanical shock testing
High-temperature operation	Junction rated to +200°C enables deployment in engine bay and transmission control units without derating
Low V_CE(sat)	230 mV @ 1A reduces conduction losses by >40% vs. typical 500 mV devices, improving efficiency in 12V systems
E-Line (TO-92 compatible) package	Enables drop-in replacement in legacy TO-92 layouts while supporting higher current and thermal performance
Lead-free & Green compliance	Fully RoHS-compliant with <900 ppm Br/Cl and <1000 ppm Sb, meeting global environmental regulations

Applications

Automotive Engine Control

Industrial Motor Drivers

Use Scenario: Switching fuel injector solenoids in 12V gasoline engines with PWM duty cycles up to 80%.

IC Role / Device Role / Timing Role: NPN power switch controlling high-side or low-side solenoid current paths.

Use Value: 6A I_CM handles inductive kickback; 60V V_CEO accommodates 40V+ flyback transients; +200°C T_J sustains operation near exhaust manifolds.

Use Scenario: Driving 24V DC brushed motors in factory automation actuators requiring intermittent 1.5A loads.

IC Role / Device Role / Timing Role: Medium-power discrete switch in H-bridge half-bridge stage or single-ended driver.

Use Value: 2A I_C and 1W P_D support continuous duty; low V_CE(sat) minimizes self-heating during 50% duty cycle operation.

LED Lighting Ballasts

Power Supply Protection Circuits

Use Scenario: Constant-current regulation for high-brightness LED strings in commercial signage powered from 24–48V supplies.

IC Role / Device Role / Timing Role: Linear pass element or PWM-controlled current sink in analog/digital dimming stages.

Use Value: Tight h_FE spread (70–300) enables predictable base drive design; 140 MHz f_T supports >10 kHz PWM dimming without phase lag.

Use Scenario: Overcurrent protection switch in 5–24V DC power distribution modules for embedded systems.

IC Role / Device Role / Timing Role: Fast-acting current-limiting transistor triggered by sense amplifier output.

Use Value: 800 ns t_off ensures rapid shutdown during fault events; 4 kV HBM ESD rating prevents latch-up from board-level transients.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX653QSTZ	Higher V_CEO = 100 V; same package and pinout; h_FE min 100 @ 1A	Better suited for 48V systems or higher-voltage flyback margins	Select when system transients exceed 60V or higher DC bus voltages are used
MJD122G	TO-220 package; 100V V_CEO; 8A I_C; higher P_D = 30W; not AEC-Q101 qualified	Requires heatsink; intended for industrial power stages, not automotive space-constrained designs	Choose only for non-automotive, high-current applications where thermal mass and board area permit TO-220 mounting

Compared with ZTX651QSTZ, ZTX653QSTZ offers higher voltage headroom in the same footprint, while MJD122G delivers greater current and power but sacrifices automotive qualification and compact packaging-making ZTX651QSTZ optimal for AEC-Q101-compliant, space-limited 12–24V switching.

Availability

ZTX651QSTZ is available at Aetrix Electronics and suitable for automotive engine control, industrial motor drivers, LED lighting ballasts, and power supply protection circuits requiring stable component supply, AEC-Q101 compliance, and through-hole manufacturability.

Supply support for ZTX651QSTZ 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 integrated circuits, specializing in high-reliability power management, signal integrity, and protection solutions.

The ZTX651QSTZ belongs to Diodes' automotive-qualified E-Line transistor family, designed specifically for medium-power switching in harsh-environment applications where thermal resilience, ESD robustness, and AEC-Q101 validation are mandatory.

FAQ

What is the difference between ZTX651QSTZ and ZTX651STZ?

ZTX651QSTZ is AEC-Q101 qualified and designated "Automotive" in ordering information, while ZTX651STZ carries standard AEC-Q101 qualification without the Automotive designation. Both share identical electrical specs, package, and pinout; the Q-marked version undergoes additional PPAP documentation and traceability per automotive customer requirements.

Can ZTX651QSTZ be used in surface-mount designs?

No-ZTX651QSTZ uses an E-Line package with joggled leads intended for through-hole mounting on PCBs. It is not designed for reflow soldering or SMT assembly. For SMT equivalents, consider Diodes' DXT651 series in SOT-23 or SOT-89 packages, which differ electrically and thermally.

What is the recommended PCB pad layout for optimal thermal performance?

For 1W operation, Diodes recommends a minimum 25 mm × 25 mm 1 oz copper pour connected to the collector lead, with 2.5 mm lead length from seating plane. Thermal resistance drops from 175°C/W (minimal pad) to 116°C/W with this layout, enabling sustained 2A conduction at +70°C ambient.

Does ZTX651QSTZ support linear (analog) operation, or is it intended only for switching?

ZTX651QSTZ supports both modes: its 140–175 MHz f_T and controlled h_FE range (70–300) make it suitable for Class-A/B audio preamplifier stages, while its low V_CE(sat) and 6A I_CM optimize it for hard-switching. Linear use requires careful thermal design due to P_D derating above +25°C.

ZTX651QSTZ Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

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

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 2 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 200mA, 2A

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 500mA, 2V

Power - Max:: 1.5 W

Frequency - Transition:: 175MHz

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

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Through Hole

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

ZTX651QSTZ FAQ

1.How can I place an order for ZTX651QSTZ through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX651QSTZ 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 ZTX651QSTZ reliable?

The price and inventory of ZTX651QSTZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX651QSTZ is usually 5 days.

3.What payment methods are accepted for ZTX651QSTZ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX651QSTZ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX651QSTZ?

ZTX651QSTZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX651QSTZ 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 ZTX651QSTZ?

For technical support, including ZTX651QSTZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX651QSTZ requirements.

6.How does Aetrix verify that ZTX651QSTZ is sourced from the original manufacturer or authorized distributors?

All ZTX651QSTZ 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 ZTX651QSTZ meets industry standards.

7.What is the process for return or replacement of ZTX651QSTZ?

All ZTX651QSTZ units undergo pre-shipment inspection (PSI). If there is an issue with ZTX651QSTZ, 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 ZTX651QSTZ part is unused and in its original packaging.

Return procedure for ZTX651QSTZ:

1.Submit a request within 90 days.

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

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