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Diodes Incorporated ZTX458STOB
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- Part No.:
- ZTX458STOB
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- E-Line-3, Formed Leads
- Datasheet:
-
ZTX458STOB.pdf
- Description:
- TRANS NPN 400V 0.3A E-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:8,681
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Product details
Overview
ZTX458STOB from Diodes Incorporated is an NPN silicon planar medium-power high-voltage transistor with VCEO = 400 V, IC = 300 mA continuous, Ptot = 1 W at Tamb = 25°C, hFE = 100–300 (IC = 1–100 mA), and fT = 50 MHz - used in flyback switch-mode power supply (SMPS) primary-side switching and industrial relay drivers.
For engineers reviewing the ZTX458STOB datasheet, ZTX458STOB pinout, ZTX458STOB application, or ZTX458STOB equivalent, key selection criteria include verified 400 V blocking capability, safe operating area (SOA) compliance up to +175°C junction temperature, low VCE(sat) (0.2–0.5 V), and TO-92-compatible E-Line package suitability for through-hole high-voltage isolation layouts.
Technical Context
This discrete NPN bipolar junction transistor operates in linear or saturated switching mode with guaranteed breakdown ratings: VCBO = VCEO = 400 V and VEBO = 5 V. Its hFE varies from 15 (IC = 100 mA) to 300 (IC = 1 mA), supporting both current amplification and robust switching across wide collector current ranges.
Thermal design is enabled by a maximum junction temperature of +200°C and storage range down to –55°C. The device exhibits Cobo = 5 pF at VCB = 20 V, f = 1 MHz, and delivers fT = 50 MHz under IC = 10 mA, VCE = 20 V - confirming suitability for medium-frequency switching above audio band.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 400 V - supports direct replacement in 380 V DC bus or 277 V AC line-switching applications without derating |
| IC (continuous) | 300 mA - enables driving 100–200 mA loads with ≥3× safety margin for transient surges |
| Ptot | 1 W at Tamb = 25°C - requires minimal heatsinking in PCB-mounted TO-92 layout with ≥1 cm² copper pour |
| hFE | 100–300 @ IC = 1–50 mA - ensures stable base drive design across production lots and temperature extremes |
| fT | 50 MHz - validates use in SMPS operating up to ~500 kHz with adequate gain margin |
| VCE(sat) | 0.2 V (IC = 20 mA, IB = 2 mA) - minimizes conduction loss in low-duty-cycle switching nodes |
| Tj(max) | +200°C - allows operation in sealed industrial enclosures with ambient up to +125°C |
Pinout & Package
Package: TO-92 compatible E-Line (3-182 outline), epoxy-molded, through-hole mount. Pin identification per standard E-Line marking: flat side facing viewer, leads down, left-to-right = Emitter (E), Base (B), Collector (C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Emitter (E) | Current sink node | Connected to ground or low-side return path; must handle full load current and thermal dissipation |
| Base (B) | Control input | Receives TTL/CMOS-compatible drive (VBE(on) = 0.9 V); requires series resistor to limit IB ≤ 6 mA |
| Collector (C) | High-voltage output node | Switches up to 400 V; electrically isolated from PCB ground plane per creepage/clearance requirements |
Key Features
| Feature | Design Value |
|---|---|
| 400 V VCEO rating | Enables direct interface with 277 VAC rectified rails or 380 VDC intermediate bus without external snubbers |
| 1 W power dissipation | Permits full-load operation at +100°C ambient with standard TO-92 footprint and no forced air |
| SOA validated to +175°C | Supports reliable pulsed operation in thermally constrained industrial control modules |
| hFE = 100–300 range | Reduces base drive circuit sensitivity to process variation and temperature drift |
| VCE(sat) ≤ 0.5 V | Limits conduction loss to < 150 mW at 300 mA, improving efficiency in intermittent duty cycles |
Applications
| Industrial Relay Driver | SMPS Primary Switch |
|---|---|
Use Scenario: Driving 24–48 VDC coil relays in PLC I/O modules with 300 VAC line isolation. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling relay coil current with galvanic separation from logic side. Use Value: 400 V VCEO prevents breakdown during inductive kickback; SOA curve supports 100 ms turn-off transients. | Use Scenario: Low-cost flyback converter primary-side switch in 5–15 W AC/DC adapters. IC Role / Device Role / Timing Role: Saturated-mode switching element synchronized to PWM controller, handling 380 VDC bus. Use Value: 1 W Ptot and 0.2 V VCE(sat) reduce thermal stress and improve light-load efficiency vs. MOSFET alternatives. |
| High-Voltage Signal Amplifier | Overvoltage Protection Circuit |
Use Scenario: Linear amplification stage for 100–300 V sensor signals in HV test equipment front-ends. IC Role / Device Role / Timing Role: Medium-gain common-emitter amplifier biased in active region with fixed VCE > 200 V. Use Value: Stable hFE and low Cobo (5 pF) preserve bandwidth up to 10 MHz in high-Z feedback paths. | Use Scenario: Crowbar element triggered by overvoltage detection in telecom power shelves. IC Role / Device Role / Timing Role: Fast-turn-on shunt switch clamping rail voltage to safe level before downstream damage occurs. Use Value: Verified VCEO(sus) = 400 V and tf < 1 µs ensure reliable crowbar action under 100 V/µs transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX450STOB | VCEO = 300 V, hFE = 100–250, Ptot = 1 W | Lower voltage rating limits use to ≤264 VAC-derived rails | Select when 300 V margin suffices and cost optimization is prioritized |
| BCV46 | VCEO = 300 V, IC = 100 mA, SOT-23 package | Lower current and surface-mount only; unsuitable for TO-92-replacement retrofits | Choose only for new SMT designs where board space is critical and voltage ≤264 VAC |
Compared with ZTX458STOB, ZTX450STOB trades 100 V headroom for broader hFE consistency, while BCV46 sacrifices package compatibility and current capacity for miniaturization - making ZTX458STOB the sole option meeting 400 V, 300 mA, and TO-92 requirements simultaneously.
Availability
ZTX458STOB is available at Aetrix Electronics and suitable for industrial relay drivers, flyback SMPS primary switches, high-voltage signal amplifiers, and overvoltage protection circuits requiring stable component supply across extended temperature and voltage ranges.
Supply support for ZTX458STOB 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 for industrial, computing, consumer, and communications markets.
ZTX458STOB belongs to the ZTX high-voltage bipolar transistor product line, engineered for reliability in mains-connected power conversion and isolation-critical control applications.
FAQ
Is ZTX458STOB RoHS compliant?
Yes, ZTX458STOB is RoHS compliant and lead-free per Diodes Incorporated's Product Change Notice #PCN-2018-003. It meets EU Directive 2011/65/EU and contains no restricted substances above threshold limits, including lead, cadmium, mercury, hexavalent chromium, PBB, and PBDE.
What is the maximum safe operating voltage for ZTX458STOB in continuous DC mode?
The absolute maximum continuous collector-emitter voltage is VCEO = 400 V at Tj ≤ +200°C. For long-term reliability, Diodes Incorporated recommends limiting VCE to ≤320 V under continuous DC conditions with adequate heatsinking and derating per the SOA curve in Figure 3 of the datasheet.
Can ZTX458STOB replace a MOSFET in a 277 VAC lighting driver?
ZTX458STOB can replace low-speed, low-frequency MOSFETs (e.g., <500 kHz) in 277 VAC-derived lighting drivers where gate drive simplicity and cost outweigh switching speed needs. Its 50 MHz fT and 0.5 V VCE(sat) support efficient linear or saturated operation, but it lacks inherent fast turn-off - external base pull-down is required.
Does ZTX458STOB require a heatsink in standard TO-92 mounting?
A heatsink is not required for ZTX458STOB at ≤300 mA and ≤25°C ambient when mounted on ≥1 cm² of 2 oz copper. At 100°C ambient or >200 mA continuous, a small clip-on aluminum heatsink (e.g., Aavid 5700 series) improves thermal margin by 25°C junction rise reduction per datasheet Figure 5.
ZTX458STOB 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):
- 300 mA
- Voltage - Collector Emitter Breakdown (Max):
- 400 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 6mA, 50mA
- Current - Collector Cutoff (Max):
- 100nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 50mA, 10V
- Power - Max:
- 1 W
- Frequency - Transition:
- 50MHz
- Operating Temperature:
- -55°C ~ 200°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- E-Line (TO-92 compatible)
ZTX458STOB FAQ
1.How can I place an order for ZTX458STOB through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTX458STOB 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 ZTX458STOB reliable?
The price and inventory of ZTX458STOB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX458STOB is usually 5 days.
3.What payment methods are accepted for ZTX458STOB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX458STOB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTX458STOB?
ZTX458STOB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTX458STOB 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 ZTX458STOB?
For technical support, including ZTX458STOB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX458STOB requirements.
6.How does Aetrix verify that ZTX458STOB is sourced from the original manufacturer or authorized distributors?
All ZTX458STOB 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 ZTX458STOB meets industry standards.
7.What is the process for return or replacement of ZTX458STOB?
All ZTX458STOB units undergo pre-shipment inspection (PSI). If there is an issue with ZTX458STOB, 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 ZTX458STOB part is unused and in its original packaging.
Return procedure for ZTX458STOB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZTX458STOB Tags
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