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

Diodes Incorporated FZT604TA

Name: FZT604TA
Brand: Diodes Incorporated
SKU: FZT604TA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FZT604TA

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: TO-261-4, TO-261AA

Datasheet:: FZT604TA.pdf

Description:: TRANS NPN DARL 100V 1.5A SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:6,899

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Product details

Overview

FZT604TA from Diodes Incorporated is an NPN silicon planar medium-power Darlington transistor in SOT223 package, rated for 100 V V_CEO, 1.5 A continuous collector current, and 2 W power dissipation. It delivers guaranteed h_FE ≥2000 at I_C = 50 mA and ≥500 at I_C = 2 A, with fast switching (t_on = 0.5 µs, t_off = 1.6 µs), and is used in high-gain DC/AC amplification and medium-current switching circuits such as relay drivers and power supply error amplifiers.

For engineers reviewing the FZT604TA datasheet, FZT604TA pinout, FZT604TA application, or FZT604TA equivalent, key selection criteria include verified Darlington gain linearity up to 2 A, V_CE(sat) ≤1.5 V at I_C = 1 A / I_B = 1 mA, thermal stability across −55°C to +150°C, and SOT223 footprint compatibility with board-level thermal management requirements.

Technical Context

The FZT604TA implements a monolithic Darlington pair structure with integrated base-emitter resistor network absent - requiring external base drive control. Its h_FE spans 500–100,000 depending on I_C (50 mA to 2 A) and V_CE (5 V), and it exhibits f_T = 150 MHz at I_C = 100 mA, enabling use in moderate-frequency switching above audio range.

Designed for linear and saturated-mode operation, it features low V_BE(sat) = 1.8 V and V_BE(on) = 1.7 V at I_C = 1 A, with C_ibo = 90 pF and C_obo = 15 pF supporting stable biasing in feedback amplifier configurations and minimizing Miller effect in switching transitions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - Maximum safe collector-emitter voltage under open-base conditions; defines upper limit for DC bus or flyback clamp applications.
I_C (continuous)	1.5 A - Sustained load current capability with 2 W P_tot and proper heatsinking; supports relay coils up to ~120 Ω @ 12 V.
h_FE @ I_C = 2 A	≥500 - Confirmed minimum current gain at full-rated current; ensures reliable saturation with ≤2 mA base drive.
V_CE(sat) @ I_C = 1 A	≤1.5 V - Low saturation voltage reduces conduction loss to <1.5 W at 1 A, critical for thermally constrained PCB layouts.
t_off	1.6 µs - Measured turn-off time under pulsed 500 mA load; enables PWM operation up to ~300 kHz with controlled fall time.
T_j range	−55°C to +150°C - Full operational junction temperature span; validated for industrial motor control and automotive under-hood auxiliary circuits.

Pinout & Package

Package: SOT223 - surface-mount, 4-pin (3 active + tab), with exposed emitter-connected thermal pad; standard JEDEC MO-178AB footprint, compatible with reflow soldering and manual prototyping.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Main emitter terminal	Internally bonded to thermal tab; must be connected to low-impedance ground plane for heat dissipation and noise immunity.
2 (Base)	Control input	Direct drive point for TTL/CMOS-compatible logic; requires series resistor to limit I_B and prevent secondary breakdown during transients.
3 (Collector)	High-side load connection	Carries full switched current; routed away from sensitive analog traces due to dI/dt-induced coupling.
Tab (Emitter)	Thermal & electrical emitter node	Electrically tied to Pin 1; provides primary thermal path to PCB copper; must not be floated or insulated.

Key Features

Feature	Design Value
Guaranteed h_FE at 2 A	Minimum 500 - Enables predictable base drive design without margin inflation for 1 A–2 A loads.
Fast switching performance	t_on/t_off = 0.5 µs / 1.6 µs - Supports clean edge transitions in 100–300 kHz PWM, reducing EMI in power converters.
High V_CEO rating	100 V - Allows direct interface with 24 V industrial buses and 48 V telecom supplies without snubbers.
Wide temperature operation	−55°C to +150°C - Validated gain and leakage stability across automotive under-hood and outdoor industrial environments.

Applications

Relay Driver Circuit

Linear Voltage Regulator Error Amplifier

Use Scenario: Driving 12 V/500 mA electromagnetic relays in PLC I/O modules with microcontroller GPIO.

IC Role / Device Role / Timing Role: Medium-power NPN Darlington switch providing >500× current gain to amplify weak MCU output into relay coil current.

Use Value: Eliminates need for discrete pre-driver stage; V_CE(sat) ≤1.5 V ensures <750 mW relay coil power loss at full activation.

Use Scenario: Error amplifier in adjustable 3 A linear regulator supplying FPGA core voltage with tight ripple control.

IC Role / Device Role / Timing Role: High-h_FE pass element driver delivering precise base current to main series pass transistor under dynamic load steps.

Use Value: Maintains loop stability across −40°C to +85°C ambient via consistent h_FE ≥2000 at I_C = 50 mA, reducing compensation complexity.

DC Motor Speed Control

High-Voltage Signal Amplifier

Use Scenario: Low-frequency PWM-controlled 24 V brushed DC motor in HVAC damper actuators.

IC Role / Device Role / Timing Role: Saturated-mode switch modulating motor current at 1–5 kHz with minimal conduction loss.

Use Value: 1.5 A I_C rating and 2 W P_tot support 25 W continuous mechanical output; t_off = 1.6 µs prevents shoot-through in half-bridge variants.

Use Scenario: Amplifying ±5 V sensor signals to ±50 V range for piezoelectric actuator drive in test equipment.

IC Role / Device Role / Timing Role: Linear-mode NPN Darlington configured in common-emitter topology with emitter degeneration.

Use Value: 100 V V_CEO and h_FE >10 kΩ at I_C = 10 mA enable stable 10× voltage gain with <0.5% THD at 10 kHz.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN Darlington transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX603	V_CEO = 80 V, h_FE min = 400 @ 1 A, SOT89 package	Limited to ≤24 V systems; lower thermal mass than SOT223	Select when board space is constrained and voltage stress remains <60 V.
MJD122G	V_CEO = 100 V, I_C = 3 A, TO-220 package, h_FE = 1000–4000 @ 1 A	Higher current and thermal capacity but requires through-hole mounting and heatsink	Choose for >2 A continuous loads or forced-air cooled industrial designs.

Compared with ZTX603 and MJD122G, the FZT604TA uniquely balances SMT manufacturability, 100 V robustness, and verified 2 A gain linearity - making it optimal for automated assembly of compact, thermally managed 24–48 V control modules where lead-free reflow compatibility and JEDEC-standard footprint are mandatory.

Availability

FZT604TA is available at Aetrix Electronics and suitable for relay drivers, linear regulator error amplifiers, DC motor speed controllers, and high-voltage signal amplifiers requiring stable component supply across industrial automation, test equipment, and building control systems.

Supply support for FZT604TA 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 devices, with emphasis on high-reliability, high-efficiency solutions for industrial, computing, and consumer markets.

The FZT604TA belongs to Diodes' medium-power bipolar transistor product line, engineered specifically for high-gain, medium-current switching and linear amplification in space-constrained, thermally demanding applications.

FAQ

What is the maximum safe operating collector current for continuous DC operation?

The FZT604TA is rated for 1.5 A continuous collector current (I_C) at T_amb = 25°C with adequate PCB copper area for heat spreading. Derating is required above 25°C ambient: linear reduction to zero at +150°C junction temperature. At 70°C ambient, max I_C drops to approximately 1.1 A with 2-layer 1 oz copper on 1 in² pad.

Does the FZT604TA require a base resistor, and what value is recommended?

Yes - a base resistor is mandatory to limit I_B and prevent thermal runaway. For 1 A collector current with h_FE ≥500, I_B ≥2 mA is needed. With 3.3 V logic drive, R_B = (3.3 V − 1.8 V)/2 mA ≈ 750 Ω; 680 Ω is standard. For 5 V drive, 1.5 kΩ is typical. Always verify with worst-case h_FE and V_BE(sat).

Can the FZT604TA be used in avalanche mode?

No - the FZT604TA is not rated or characterized for controlled avalanche operation. Its absolute maximum V_CBO = 120 V and V_CEO = 100 V define hard breakdown limits. Exceeding V_CEO risks irreversible second breakdown. Use external clamping (e.g., TVS diode) for inductive load flyback protection.

Is the thermal tab electrically isolated?

No - the exposed thermal tab is internally connected to the emitter (Pin 1). It must be soldered directly to an emitter-node copper pour. Insulating the tab or routing unrelated signals beneath it violates the device's thermal and electrical design, risking overheating and latch-up.

FZT604TA Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Digi-Reel®

Product Status:: Obsolete

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 1.5 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 1mA, 1A

Current - Collector Cutoff (Max):: 10µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 2000 @ 1A, 5V

Power - Max:: 2 W

Frequency - Transition:: 150MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223-3

FZT604TA FAQ

1.How can I place an order for FZT604TA through Aetrix?

Please submit a Request for Quotation (RFQ) for FZT604TA 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 FZT604TA reliable?

The price and inventory of FZT604TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT604TA is usually 5 days.

3.What payment methods are accepted for FZT604TA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT604TA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FZT604TA?

FZT604TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FZT604TA 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 FZT604TA?

For technical support, including FZT604TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT604TA requirements.

6.How does Aetrix verify that FZT604TA is sourced from the original manufacturer or authorized distributors?

All FZT604TA 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 FZT604TA meets industry standards.

7.What is the process for return or replacement of FZT604TA?

All FZT604TA units undergo pre-shipment inspection (PSI). If there is an issue with FZT604TA, 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 FZT604TA part is unused and in its original packaging.

Return procedure for FZT604TA:

1.Submit a request within 90 days.

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

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