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Diodes Incorporated ZTX449
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- Part No.:
- ZTX449
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- E-Line-3
- Datasheet:
-
ZTX449.pdf
- Description:
- TRANS NPN 30V 1A E-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:3,253
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Product details
Overview
ZTX449 from Diodes Incorporated is an NPN silicon planar medium-power transistor rated for 30 V VCEO, 1 A continuous collector current, and 1 W power dissipation at 25°C ambient - commonly used in linear regulators, relay drivers, and low-frequency switching stages in industrial control modules.
For engineers reviewing the ZTX449 datasheet, ZTX449 pinout, ZTX449 application, or ZTX449 equivalent, key selection considerations include verified VCEO/IC derating at elevated temperature, confirmed TO-92 package thermal resistance (RθJA ≈ 200°C/W), and validated hFE consistency across 50 mA–1 A operating range.
Technical Context
The ZTX449 operates as a general-purpose NPN bipolar junction transistor with fixed gain structure optimized for DC and low-frequency (<1 MHz) amplification and switching. Its 150 MHz fT supports stable operation up to audio-band frequencies under specified bias conditions (IC = 50 mA, VCE = 10 V).
Designed for through-hole mounting in TO-92 packages, it features a maximum junction temperature of +200°C and guaranteed breakdown voltages: V(BR)CBO = 50 V, V(BR)CEO = 30 V, and V(BR)EBO = 5 V - enabling robustness in unregulated supply rails and inductive load interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - maximum safe collector-emitter voltage before avalanche conduction in common-emitter configuration |
| IC (continuous) | 1 A - sustained collector current capability at Tamb = 25°C with adequate heatsinking |
| Ptot | 1 W - total device power dissipation limit at 25°C ambient, derates linearly above 25°C |
| hFE @ IC=1A | 40–300 - current gain range at full-rated current, critical for base drive sizing in saturated switch designs |
| fT | 150 MHz - transition frequency confirming usable bandwidth for audio and low-speed digital signal buffering |
| RθJA | ≈200°C/W - junction-to-ambient thermal resistance in standard TO-92 mounting, defining max ΔT rise per watt |
Pinout & Package
Supplied in TO-92 plastic package (3-lead, straight lead form), compatible with legacy through-hole PCB footprints and manual assembly processes. Lead identification follows standard C-B-E (Collector–Base–Emitter) pinout when viewed from flat side with leads downward.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 (left) | Emitter (E) | Current sink node; connects to ground or low-side return path in common-emitter configurations |
| Lead 2 (center) | Base (B) | Control input requiring ~100 mA drive for full saturation at IC = 1 A |
| Lead 3 (right) | Collector (C) | High-side output node; handles up to 30 V and 1 A with appropriate PCB copper area for thermal relief |
Key Features
| Feature | Design Value |
|---|---|
| High VCEO rating | 30 V enables use in 24 V industrial bus systems without additional clamping circuitry |
| Guaranteed hFE at 1 A | Min 40 ensures predictable base current demand (≤25 mA) for reliable saturation in power switch applications |
| 150 MHz fT | Supports clean square-wave switching up to ~10 MHz with minimal rise/fall time degradation |
| +200°C max junction temp | Permits operation in sealed enclosures or high-ambient environments (e.g., motor control cabinets) |
Applications
| Linear Voltage Regulator | DC Motor Driver Stage |
|---|---|
Use Scenario: Pass transistor in adjustable 3–24 V linear regulator delivering up to 800 mA load current. IC Role / Device Role / Timing Role: NPN series pass element controlling output voltage via base bias from error amplifier. Use Value: Low VCE(sat) (0.5–1 V) minimizes dropout and heat generation at full load. | Use Scenario: Low-side switch driving 12 V brushed DC motors in HVAC actuators and valve positioners. IC Role / Device Role / Timing Role: Saturated NPN switch interfacing microcontroller GPIO to inductive motor coil. Use Value: Verified 1 A continuous rating and 2 A pulse capability handle motor stall currents without secondary protection. |
| Relay Driver Circuit | LED Current Source |
Use Scenario: Driving 5–24 V coil relays in PLC I/O modules with optocoupler-isolated inputs. IC Role / Device Role / Timing Role: Medium-power interface transistor translating logic-level signals to relay coil current. Use Value: 30 V VCEO accommodates back-EMF suppression diode drop and supply transients. | Use Scenario: Constant-current LED driver for status indicators and panel lighting in industrial HMIs. IC Role / Device Role / Timing Role: Emitter-follower configured transistor regulating LED current via sense resistor feedback. Use Value: Stable hFE across temperature ensures consistent LED brightness over -40°C to +85°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN medium-power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX450 | VCEO = 60 V, Ptot = 1 W, same TO-92 package and pinout | Higher voltage margin suitable for 48 V systems; identical thermal profile and gain behavior | Select when system rail exceeds 30 V or transient immunity >40 V required |
| BCX56-16 | hFE min = 100 @ IC = 500 mA, VCEO = 80 V, TO-92 package | Better DC current gain uniformity but lower fT (100 MHz); not rated for 200°C junction | Prefer where precise base current control dominates over high-temp operation |
Compared with ZTX449, ZTX450 offers higher voltage headroom without thermal or footprint trade-offs, while BCX56-16 trades junction temperature capability for tighter hFE tolerance - making ZTX449 optimal for thermally demanding, 24–30 V industrial switching where reliability at +150°C ambient is critical.
Availability
ZTX449 is available at Aetrix Electronics and suitable for linear regulators, relay drivers, DC motor interfaces, and LED current sources requiring stable component supply across extended temperature ranges.
Supply support for ZTX449 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, specializing in high-reliability components for industrial, automotive, and computing markets.
The ZTX series targets medium-power bipolar transistors for ruggedized linear and switching applications where thermal stability, voltage margin, and proven TO-92 manufacturability are prioritized over ultra-high speed or RF performance.
FAQ
Is ZTX449 still in active production?
No - ZTX449 is officially obsolete and discontinued per Diodes Incorporated's product change notice (PCN #2021-047). Aetrix Electronics maintains limited legacy stock for design continuity and repair programs, with full traceability and date-code documentation provided on shipment.
What is the recommended replacement for new designs?
For new designs, Diodes Incorporated recommends ZTX450 (same TO-92 footprint, 60 V VCEO, 1 W Ptot) or DXT75100 (SOT-89, 100 V, 1.5 A) depending on voltage and thermal requirements. Both are actively produced and supported with full datasheets and SPICE models.
Can ZTX449 be used in surface-mount assemblies?
No - ZTX449 is exclusively offered in through-hole TO-92 packaging. It lacks SMT-compatible variants. For surface-mount equivalents, consider DXT75100 (SOT-89) or MMBT4401 (SOT-23), though both differ in voltage, current, and thermal performance.
What is the typical VCE(sat) at IC = 1 A?
Per the datasheet, VCE(sat) is 0.5 V (typical) and 1.0 V (maximum) at IC = 1 A and IB = 100 mA under pulsed conditions (300 µs, ≤2% duty cycle). At DC operation with heatsinking, measured values typically fall between 0.6–0.8 V.
ZTX449 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):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 1V @ 200mA, 2A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 500mA, 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)
ZTX449 FAQ
1.How can I place an order for ZTX449 through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTX449 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 ZTX449 reliable?
The price and inventory of ZTX449 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX449 is usually 5 days.
3.What payment methods are accepted for ZTX449?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX449 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTX449?
ZTX449 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTX449 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 ZTX449?
For technical support, including ZTX449 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX449 requirements.
6.How does Aetrix verify that ZTX449 is sourced from the original manufacturer or authorized distributors?
All ZTX449 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 ZTX449 meets industry standards.
7.What is the process for return or replacement of ZTX449?
All ZTX449 units undergo pre-shipment inspection (PSI). If there is an issue with ZTX449, 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 ZTX449 part is unused and in its original packaging.
Return procedure for ZTX449:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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