My Inquiry
My Account
Diodes Incorporated ZTX551STOB
,TO-226_straightlead.jpg)
- Part No.:
- ZTX551STOB
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- E-Line-3, Formed Leads
- Datasheet:
-
ZTX551STOB.pdf
- Description:
- TRANS PNP 60V 1A E-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:6,458
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ZTX551STOB from Diodes Incorporated is an 80V PNP medium-power bipolar junction transistor in E-Line (TO-92 compatible) package, rated for -1A continuous collector current, -65V VCEO, and 1W power dissipation at +25°C ambient. It operates up to +200°C junction temperature and is used in DC-DC converter switching stages, LCD backlight drivers, and emergency lighting power control circuits.
For engineers reviewing the ZTX551STOB datasheet, ZTX551STOB pinout, ZTX551STOB application, or ZTX551STOB equivalent, key selection criteria include its -65V VCEO, -1A IC, hFE range of 50–150 at -1A, -350mV VCE(sat) at -150mA/-15mA, and E-Line mechanical compatibility with TO-92 footprint constraints.
Technical Context
This PNP transistor delivers high-voltage switching capability with a minimum BVCEO of -65V and supports pulsed operation up to -2A peak current. Its thermal resistance junction-to-ambient is 175°C/W under standard PCB mounting (12mm lead length), enabling reliable performance in compact, thermally constrained power stages.
The device features a DC current gain (hFE) of 10–150 across operating conditions: 50–150 at IC = -150mA/VCE = -10V and 10–50 at IC = -1A/VCE = -10V. Its fT of 150MHz ensures adequate bandwidth for medium-frequency switching applications such as PWM-controlled LED drivers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -65 V - Maximum allowable collector-emitter voltage before breakdown under open-base condition |
| IC (continuous) | -1 A - Sustained collector current rating defining steady-state power stage capacity |
| PD | 1 W - Power dissipation limit at TA = +25°C with standard PCB mounting |
| VCE(sat) | -350 mV - Low saturation voltage at IC = -150mA/IB = -15mA, minimizing conduction loss |
| hFE | 50–150 - DC current gain range at IC = -150mA/VCE = -10V, supporting stable base drive design |
| fT | 150 MHz - Transition frequency indicating usable bandwidth for switching above 100kHz |
| TJ max | +200°C - Maximum junction temperature enabling operation in high-ambient industrial environments |
Pinout & Package
E-Line package: molded plastic, TO-92 compatible outline with matte tin-plated leads; dimensions per Diodes Package Outline E-Line (A=2.28mm, D=4.57mm, E=3.90mm, L=13.50mm); weight ≈0.159g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Emitter (E) | Current source terminal for PNP operation | Connected to higher potential rail; defines reference for base bias and collector load |
| Collector (C) | Current sink terminal | Typically tied to load (e.g., LED string cathode or inductor return) in low-side switch configuration |
| Base (B) | Control input | Receives negative current to turn on; requires series resistor to limit IB per hFE and VBE(sat) ≈ -1.1V |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage blocking | BVCEO = -65V enables use in 48V and 60V DC bus applications without derating |
| Thermal robustness | +200°C maximum junction temperature supports operation in sealed or high-ambient enclosures |
| Lead-free & green compliance | Fully RoHS 3 compliant with <900ppm Br/Cl and <1000ppm Sb, suitable for automotive and industrial eco-design |
| ESD resilience | 4kV HBM rating reduces risk of handling damage during manual assembly or rework |
Applications
| LCD Backlight Converters | Emergency Lighting Drivers |
|---|---|
Use Scenario: Step-up DC-DC converter driving parallel white LED strings in notebook or monitor displays. IC Role / Device Role / Timing Role: PNP switch controlling energy transfer into boost inductor during off-time of main controller. Use Value: -65V VCEO safely handles reflected inductive kickback; -350mV VCE(sat) limits conduction loss at 350mA typical LED current. | Use Scenario: Constant-current driver powering LED arrays in battery-backed exit signs or safety lighting units. IC Role / Device Role / Timing Role: Linear or PWM-controlled pass element regulating current through high-brightness LEDs. Use Value: +200°C TJ(max) ensures reliability during extended battery discharge cycles in unventilated housings. |
| Industrial DC-DC Modules | Low-Power Relay Drivers |
Use Scenario: Isolated flyback or forward converter auxiliary supply generating +12V/-12V rails for gate drivers or sensors. IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier or output switch in low-cost non-isolated topologies. Use Value: 1W power rating and 175°C/W RθJA allow direct mounting on small PCBs without heatsinks in <5W modules. | Use Scenario: Driving 12V/24V electromagnetic relays in PLC I/O modules or building automation controllers. IC Role / Device Role / Timing Role: High-side or low-side switch interfacing microcontroller GPIO to relay coil. Use Value: -1A IC comfortably exceeds typical relay coil currents (40–150mA), providing margin for inrush and aging. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP medium-power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX550 | Lower -45V VCEO and -250mV VCE(sat); obsolete per Diodes' ordering info | Not recommended for >40V bus designs; limited headroom in boost converters | Select only if legacy redesign mandates identical marking and lower saturation voltage is critical |
| MPSA92 | -300V VCEO, -500mV VCE(sat) at -10mA, lower hFE (25–100), same E-Line package | Better for high-voltage AC line-derived supplies; higher VCE(sat) increases loss at >100mA | Choose when >100V isolation or creepage requirements dominate over conduction efficiency |
Compared with ZTX551STOB, ZTX550 offers lower saturation voltage but insufficient voltage rating for modern 48V systems, while MPSA92 trades conduction loss for extreme voltage margin-making ZTX551STOB the optimal balance for 36–60V industrial DC-DC and LED driver applications.
Availability
ZTX551STOB is available at Aetrix Electronics and suitable for LCD backlight converters, emergency lighting drivers, and industrial DC-DC modules requiring stable component supply and long-term manufacturing continuity.
Supply support for ZTX551STOB 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 North America.
ZTX551STOB belongs to Diodes' general-purpose bipolar transistor product line, engineered for cost-sensitive, medium-power linear and switching applications in industrial, consumer, and automotive-qualified systems.
FAQ
What is the maximum safe operating voltage for ZTX551STOB in a DC-DC converter?
The ZTX551STOB has a guaranteed minimum VCEO of -65V and VCBO of -80V. For reliable operation in DC-DC converters, design peak collector-emitter voltage to ≤ -52V (80% of -65V) to maintain margin against transients and temperature drift. This ensures robustness in 48V nominal bus applications with expected ripple and switching overshoot.
Can ZTX551STOB replace ZTX550 in existing PCB layouts?
Yes-ZTX551STOB uses the identical E-Line package and pinout (Emitter-Collector-Base) as ZTX550, making it a direct physical and electrical drop-in replacement. However, its higher -65V VCEO and slightly higher VCE(sat) (-350mV vs. -250mV) require verification of base drive strength and thermal margin in high-current, high-duty-cycle operation.
Is ZTX551STOB qualified for automotive applications?
No-ZTX551STOB is not AEC-Q101 qualified. Diodes offers automotive-grade variants with Q-suffix (e.g., ZTX551Q) that undergo additional stress testing, PPAP documentation, and IATF 16949 manufacturing controls. Use ZTX551Q for automotive lighting or body control modules where qualification is mandatory.
How does the E-Line package compare to standard TO-92 in PCB assembly?
The E-Line package matches TO-92 mechanical dimensions and lead spacing (2.54mm), allowing use of existing TO-92 pick-and-place tooling and reflow profiles. Its matte tin-plated leads meet MIL-STD-202 solderability requirements, and the 0.159g weight minimizes board flex stress-enabling seamless integration into legacy and new designs without layout changes.
ZTX551STOB 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:
- PNP
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 60 V
- Vce Saturation (Max) @ Ib, Ic:
- 350mV @ 15mA, 150mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 150mA, 10V
- 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)
ZTX551STOB FAQ
1.How can I place an order for ZTX551STOB through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTX551STOB 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 ZTX551STOB reliable?
The price and inventory of ZTX551STOB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX551STOB is usually 5 days.
3.What payment methods are accepted for ZTX551STOB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX551STOB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTX551STOB?
ZTX551STOB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTX551STOB 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 ZTX551STOB?
For technical support, including ZTX551STOB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX551STOB requirements.
6.How does Aetrix verify that ZTX551STOB is sourced from the original manufacturer or authorized distributors?
All ZTX551STOB 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 ZTX551STOB meets industry standards.
7.What is the process for return or replacement of ZTX551STOB?
All ZTX551STOB units undergo pre-shipment inspection (PSI). If there is an issue with ZTX551STOB, 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 ZTX551STOB part is unused and in its original packaging.
Return procedure for ZTX551STOB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZTX551STOB Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
Tech Hub
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…
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…
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…
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…
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…
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.
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.…
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…
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…
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…
