Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Diodes Incorporated ZTX1056A

Name: ZTX1056A
Brand: Diodes Incorporated
SKU: ZTX1056A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: ZTX1056A

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3

Datasheet:: ZTX1056A.pdf

Description:: TRANS NPN 160V 3A E-LINE

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:9,873

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

ZTX1056A from Zetex (now Diodes Incorporated) is an NPN silicon planar medium-power high-gain transistor rated for 160 V V_CEO, 3 A continuous collector current, and 6 A pulse current, with V_CE(sat) as low as 25 mV at I_C=0.1 A/I_B=5 mA. It operates from −55 °C to +200 °C and is used in industrial switching, linear regulator pass elements, and high-reliability DC-DC converter output stages.

For engineers reviewing the ZTX1056A datasheet, ZTX1056A pinout, ZTX1056A application, or ZTX1056A equivalent, key selection criteria include its 160 V breakdown rating, 275–1200 h_FE range across 10 mA–6 A, low 25–300 mV saturation voltage under varying load conditions, and TO-92-compatible E-Line package thermal performance up to +200 °C junction temperature.

Technical Context

The ZTX1056A is a discrete bipolar junction transistor optimized for medium-power linear and switching operation. Its high h_FE (min 275 at 10 mA, min 30 at 3 A) enables efficient base drive in low-loss emitter-follower and series-pass configurations, while its 1 W P_tot at T_amb=25 °C and transient thermal resistance profile support pulsed operation up to 6 A with controlled duty cycle.

Electrical behavior is characterized by tight V_(BR)CBO/V_CEO distribution (200–310 V), low leakage (ICBO ≤ 10 nA at 150 V), and f_T = 120 MHz at 50 mA/10 V - confirming suitability for audio-frequency amplification and fast-switching applications below 10 MHz where gain-bandwidth trade-offs are critical.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - maximum safe collector-emitter voltage before avalanche in common-emitter configuration
I_C Continuous	3 A - continuous DC collector current capability with adequate heatsinking at 25 °C ambient
V_CE(sat)	25–300 mV - collector-emitter saturation voltage across 0.1–3 A loads, directly impacting conduction loss in switch mode
h_FE	275–1200 - DC current gain spanning 10 mA to 6 A, enabling scalable base drive design
f_T	120 MHz - transition frequency at 50 mA/10 V, limiting usable bandwidth in small-signal amplification
T_j Range	−55 °C to +200 °C - extended junction temperature rating for aerospace, downhole, or high-temp industrial use
P_tot	1 W - total power dissipation limit at 25 °C ambient, derating linearly above that temperature

Pinout & Package

Package: TO-92-compatible E-Line plastic package with standard lead spacing and outline per Zetex Issue 3 (Jan 1995). Leads are arranged in straight-line configuration with emitter (E), base (B), and collector (C) terminals identified on device marking and datasheet diagram.

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current exit path in NPN operation	Low-impedance terminal for return current; connected to ground or low-side reference in most topologies
B (Base)	Control electrode for minority-carrier injection	Requires precise current-limited drive (max 500 mA) to avoid second breakdown during switching transients
C (Collector)	Current entry path under forward active/saturation	High-voltage node handling up to 160 V; electrically isolated from mounting surface in TO-92 package

Key Features

Feature	Design Value
High V_CEO with low leakage	160 V rating and ICBO ≤ 10 nA at 150 V supports stable operation in high-impedance bias networks
Wide h_FE range across current	275–1200 gain ensures predictable base drive scaling from signal-level to 3 A load conditions
Low V_CE(sat) at high current	140 mV at I_C=2 A/I_B=100 mA reduces conduction loss in linear regulators and motor drivers
Extended temperature operation	Rated for −55 °C to +200 °C junction operation, validated for harsh-environment reliability testing
SPICE-model supported	Validated 1995 SPICE model (IS=1.41E-12, BF=600, VAF=120) enables accurate circuit simulation

Applications

Industrial Linear Regulators

High-Temperature Sensor Signal Conditioning

Use Scenario: Used as series pass element in adjustable 3-terminal linear regulators delivering up to 2.5 A at 12–48 V input.

IC Role / Device Role / Timing Role: NPN pass transistor operating in active region, dissipating up to 1 W continuously with thermal foldback protection.

Use Value: Low V_CE(sat) (≤140 mV at 2 A) minimizes dropout voltage and improves efficiency over wide load range.

Use Scenario: Amplifies low-level thermocouple or RTD signals in oil & gas downhole tools operating at 175 °C ambient.

IC Role / Device Role / Timing Role: Discrete NPN configured as DC-coupled amplifier stage with matched bias network.

Use Value: Stable h_FE and leakage (ICBO ≤ 10 nA) maintained across −55 °C to +200 °C enable calibrated gain accuracy without recalibration.

DC-DC Converter Output Stage

Relay/Valve Driver Interface

Use Scenario: Drives synchronous rectifier or flyback secondary in isolated 24 V input, 5 V/3 A output converters.

IC Role / Device Role / Timing Role: Medium-speed switching transistor with ton=110 ns/toff=2450 ns, operated in saturated switch mode.

Use Value: 6 A pulse rating and 120 MHz f_T allow reliable operation at 100–500 kHz switching frequencies with controlled turn-off tail.

Use Scenario: Interfaces microcontroller GPIO to 24 V industrial relay coils or solenoid valves requiring 100–500 mA drive.

IC Role / Device Role / Timing Role: Single-stage NPN switch with base resistor network, providing galvanic isolation and current gain.

Use Value: High h_FE (≥400 at 100 mA) reduces required MCU drive current; 160 V V_CEO withstands inductive kickback without snubber.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX855	Higher V_CEO (200 V), same TO-92 package, h_FE min 300 at 10 mA, V_CE(sat) 100 mV @ 2 A	Direct replacement with improved voltage margin and tighter gain spec; recommended for new designs	Select ZTX855 when designing for >160 V bus rails or requiring guaranteed minimum h_FE ≥300 at low current
MJD112	TO-220 package, 100 V V_CEO, 2 A continuous, higher P_tot (1.5 W), lower f_T (3 MHz)	Not pin-compatible; requires PCB redesign but offers higher power handling and thermal mass	Choose MJD112 only when thermal budget exceeds TO-92 limits and voltage requirements are ≤100 V

Compared with ZTX1056A, ZTX855 provides higher voltage headroom and tighter gain consistency for new designs, while MJD112 trades package size and voltage rating for greater thermal capacity - neither is drop-in compatible, and ZTX855 is explicitly designated as the preferred migration path per Zetex documentation.

Availability

ZTX1056A is available at Aetrix Electronics and suitable for industrial linear regulators, high-temperature sensor interfaces, and relay driver circuits requiring stable component supply despite its obsolete status.

Supply support for ZTX1056A 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

Zetex plc, founded in the UK and acquired by Diodes Incorporated in 2008, specialized in high-performance discrete semiconductors for demanding analog and power applications.

The ZTX series was developed for medium-power linear and switching applications requiring extended temperature operation, high gain consistency, and robust SOA - targeting industrial control, aerospace, and energy infrastructure markets.

FAQ

Is ZTX1056A still in active production?

No. ZTX1056A is officially obsolete per Zetex documentation dated January 1995, with ZTX855 designated as the direct replacement. Aetrix Electronics supplies remaining original-stock ZTX1056A for legacy repair and continuity programs, with full traceability and test validation.

What is the maximum safe operating voltage for ZTX1056A in switching applications?

The absolute maximum collector-emitter voltage is 160 V (V_CEO). In practice, design margins require limiting steady-state V_CE to ≤120 V and transient spikes to ≤140 V, especially with inductive loads, to ensure long-term reliability and avoid second breakdown.

Can ZTX1056A be used in parallel for higher current?

Parallel operation is not recommended due to gain mismatch and thermal runaway risk. The h_FE variation (275–1200) and positive temperature coefficient of V_BE(sat) make current sharing unstable without individual emitter resistors and matched thermal coupling - use a single higher-rated device instead.

Does ZTX1056A have a qualified SPICE model for simulation?

Yes. An official SPICE model was released by Zetex in January 1995 (revision 24/1/95), including parameters for IS, BF, VAF, CJC, CJE, TF, and TR. It is validated for DC, AC, and transient analysis at 25 °C and supports basic temperature scaling in commercial simulators.

ZTX1056A Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: E-Line-3

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 160 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 200mA, 3A

Current - Collector Cutoff (Max):: 10nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 300 @ 500mA, 10V

Power - Max:: 1 W

Frequency - Transition:: 120MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

ZTX1056A FAQ

1.How can I place an order for ZTX1056A through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX1056A 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 ZTX1056A reliable?

The price and inventory of ZTX1056A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX1056A is usually 5 days.

3.What payment methods are accepted for ZTX1056A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX1056A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX1056A?

ZTX1056A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX1056A 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 ZTX1056A?

For technical support, including ZTX1056A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX1056A requirements.

6.How does Aetrix verify that ZTX1056A is sourced from the original manufacturer or authorized distributors?

All ZTX1056A 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 ZTX1056A meets industry standards.

7.What is the process for return or replacement of ZTX1056A?

All ZTX1056A units undergo pre-shipment inspection (PSI). If there is an issue with ZTX1056A, 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 ZTX1056A part is unused and in its original packaging.

Return procedure for ZTX1056A:

1.Submit a request within 90 days.

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

Tech Hub

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…

2026-07-20 Product Change Notification (PCN) in Electronic Components: Meaning and Supply Chain Response

Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…

2026-07-19 Blend Door Actuator: Symptoms, Location, Reset and Replacement Guide

A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…