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

Diodes Incorporated ZTX1048ASTOB

Name: ZTX1048ASTOB
Brand: Diodes Incorporated
SKU: ZTX1048ASTOB
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ZTX1048ASTOB

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: E-Line-3, Formed Leads

Datasheet:: ZTX1048ASTOB.pdf

Description:: TRANS NPN 17.5V 4A E-LINE

Quantity:: RFQ Add To RFQ list

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Inventory:8,463

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Product details

Overview

ZTX1048A from Diodes Incorporated is an NPN silicon planar medium-power high-gain transistor rated for V_CEO = 17.5 V, I_C = 4 A continuous, and P_tot = 1 W at +25°C, with h_FE up to 1200 at I_C = 10 mA and V_CE = 2 V; it serves as a switching and amplification device in DC-DC converter power stages and LCD backlight drivers.

For engineers reviewing the ZTX1048A datasheet, ZTX1048A pinout, ZTX1048A application, or ZTX1048A equivalent, key selection criteria include its 20 A pulse current capability, low V_CE(sat) (as low as 27 mV at I_C = 0.5 A / I_B = 10 mA), high f_T of 150 MHz, and E-Line package thermal performance for automotive-grade power switching.

Technical Context

The ZTX1048A operates as a medium-power NPN bipolar junction transistor optimized for fast-switching applications requiring high DC current gain and low saturation voltage. Its SPICE model includes BF = 550, VAF = 120 V, and IKF = 8.0 A, indicating robust forward-active behavior and moderate early voltage linearity.

It supports pulsed operation up to 20 A with defined switching times (t_on = 130 ns, t_off = 180 ns under I_C = 4 A, V_CC = 10 V), and exhibits C_obo = 60–80 pF at V_CB = 10 V, enabling stable high-frequency switching in flyback and boost topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	17.5 V - Maximum safe collector-emitter voltage under open-base conditions; defines usable headroom in low-voltage DC-DC switch nodes.
I_C (cont.)	4 A - Continuous collector current rating; sets thermal design baseline for heatsink sizing in 1 W dissipation scenarios.
h_FE	280–1200 - DC current gain range across operating points; enables precise base drive sizing for linear or saturated switching.
V_CE(sat)	27–245 mV - Saturation voltage span across I_C = 0.5–4 A; directly determines conduction loss in power stage designs.
f_T	150 MHz - Transition frequency at I_C = 50 mA, V_CE = 10 V; confirms suitability for >1 MHz switching in compact converters.
t_on/t_off	130/180 ns - Turn-on/turn-off delays under specified test conditions; constrains minimum achievable switching period.
P_tot	1 W - Total power dissipation at T_amb = +25°C; establishes derating curve for ambient temperature and PCB copper area.

Pinout & Package

The ZTX1048A is housed in the E-Line (TO-92 variant) package: molded plastic case with 3 leads, 13.5 mm typical body length, 4.57 mm D dimension, and 3.90 mm E width; designed for through-hole mounting with standardized pad layout per Diodes' package outline documentation.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal	Low-impedance return path; connects to ground or low-side shunt in switching configurations.
Base (B)	Control input	Receives current-limited drive signal; requires external resistor to limit I_B ≤ 500 mA peak.
Collector (C)	Current source terminal	High-side connection to load or inductor; handles full switched current and voltage transients.

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 280 at I_C = 10 mA - reduces required base drive power and simplifies driver circuitry.
Low V_CE(sat)	27 mV min at I_C = 0.5 A - cuts conduction losses by >50% vs. standard general-purpose transistors in same package.
20 A pulse rating	ICM = 20 A - supports short-duration surge handling in LED flash or emergency lighting strobe circuits.
High f_T	150 MHz - enables stable operation in >1 MHz PWM control loops without gain roll-off.
AEC-Q101 readiness	Qualified for automotive change control - meets PPAP requirements and is manufactured in IATF 16949-certified facilities.

Applications

LCD Backlight Converter

Emergency Lighting Driver

Use Scenario: Boost converter driving parallel white LED strings in automotive instrument clusters.

IC Role / Device Role / Timing Role: Main switching transistor in primary-side power stage, operating at 200–500 kHz.

Use Value: Low V_CE(sat) minimizes heat generation in confined space; high h_FE allows direct MCU GPIO drive without buffer stage.

Use Scenario: Constant-current source for battery-backed LED arrays in fire alarm panels.

IC Role / Device Role / Timing Role: Linear or PWM-controlled current regulator delivering up to 4 A to LED load.

Use Value: 17.5 V V_CEO accommodates 12 V nominal supply with ripple margin; 20 A pulse rating supports flash-mode overdrive.

DC-DC Buck Regulator

Automotive Interior Lighting Control

Use Scenario: Synchronous rectifier replacement in non-isolated buck converter for infotainment power rail.

IC Role / Device Role / Timing Role: Low-side switch controlling inductor current flow during freewheeling phase.

Use Value: Fast t_off = 180 ns limits dead-time losses; E-Line package provides mechanical stability under vibration.

Use Scenario: Dimmable ambient lighting module using PWM-controlled current sink for RGB LEDs.

IC Role / Device Role / Timing Role: High-gain current amplifier translating low-current PWM signal into 4 A output.

Use Value: h_FE up to 1200 at I_C = 20 A enables single-transistor scaling from microcontroller logic levels.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX1050A	V_CEO = 30 V, h_FE = 200–600, P_tot = 1 W, same E-Line package	Higher V_CEO but lower gain; suited for 24 V systems where voltage margin is critical	Select when system bus voltage exceeds 17.5 V but gain requirements are relaxed.
BCP56-10	SOT-223 package, V_CEO = 80 V, h_FE = 100–300, P_tot = 1.5 W, surface-mount	Higher voltage rating and power dissipation, but lower gain and different footprint	Choose for automated assembly or higher-voltage industrial supplies where board space permits SMT.

Compared with ZTX1050A and BCP56-10, the ZTX1048A offers superior current gain and lowest V_CE(sat) in through-hole E-Line format-ideal for cost-sensitive, high-efficiency 12 V automotive lighting and converter designs where manual or wave-solder assembly is used.

Availability

ZTX1048A is available at Aetrix Electronics and suitable for LCD backlight converters, emergency lighting drivers, and DC-DC buck regulators requiring stable component supply and long-term production continuity.

Supply support for ZTX1048A 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, manufacturing, and sales operations across Asia, Europe, and the Americas.

The ZTX series targets medium-power bipolar switching applications in automotive, industrial, and consumer power management, emphasizing high gain, low saturation, and AEC-Q101-aligned reliability.

FAQ

Is the ZTX1048A qualified for automotive applications?

Yes-the ZTX1048A is manufactured in IATF 16949-certified facilities and supports PPAP documentation; while not formally AEC-Q101 certified on datasheet, Diodes states it meets automotive change control requirements and is intended for automotive-grade designs requiring specific qualification pathways.

What is the maximum allowable junction temperature for continuous operation?

The ZTX1048A has an operating junction temperature range of –55°C to +200°C. For continuous operation at full 4 A collector current, thermal design must ensure T_J remains ≤ +150°C to maintain reliability, requiring appropriate PCB copper area or heatsinking per the E-Line thermal resistance profile.

Can the ZTX1048A replace a BC337 in existing designs?

No-while both are NPN transistors, the ZTX1048A delivers 4 A continuous current and 1 W dissipation versus BC337's 0.5 A and 0.625 W; substituting without redesign risks thermal runaway and premature failure due to mismatched gain, saturation voltage, and thermal mass.

Does Diodes provide SPICE models for the ZTX1048A?

Yes-the official datasheet includes a verified SPICE model with parameters IS=13.73E-13, BF=550, VAF=120, CJC=136E-12, and TF=600E-12, validated for transient and AC analysis in standard simulators such as LTspice and PSpice.

ZTX1048ASTOB 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:: NPN

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 17.5 V

Vce Saturation (Max) @ Ib, Ic:: 245mV @ 20mA, 4A

Current - Collector Cutoff (Max):: 10nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 300 @ 1A, 2V

Power - Max:: 1 W

Frequency - Transition:: 150MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

ZTX1048ASTOB FAQ

1.How can I place an order for ZTX1048ASTOB through Aetrix?

Please submit a Request for Quotation (RFQ) for ZTX1048ASTOB 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 ZTX1048ASTOB reliable?

The price and inventory of ZTX1048ASTOB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX1048ASTOB is usually 5 days.

3.What payment methods are accepted for ZTX1048ASTOB?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX1048ASTOB transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ZTX1048ASTOB?

ZTX1048ASTOB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ZTX1048ASTOB 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 ZTX1048ASTOB?

For technical support, including ZTX1048ASTOB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX1048ASTOB requirements.

6.How does Aetrix verify that ZTX1048ASTOB is sourced from the original manufacturer or authorized distributors?

All ZTX1048ASTOB 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 ZTX1048ASTOB meets industry standards.

7.What is the process for return or replacement of ZTX1048ASTOB?

All ZTX1048ASTOB units undergo pre-shipment inspection (PSI). If there is an issue with ZTX1048ASTOB, 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 ZTX1048ASTOB part is unused and in its original packaging.

Return procedure for ZTX1048ASTOB:

1.Submit a request within 90 days.

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

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