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onsemi BZX84C51LT1
- Part No.:
- BZX84C51LT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84C51LT1.pdf
- Description:
- DIODE ZENER 51V 225MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:84,000
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Product details
Overview
BZX84C51LT1 from onsemi is a 51 V, ±5% tolerance Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board at 25°C, with 180 Ω dynamic impedance at 5 mA test current and 100 µA reverse leakage at 38.3 V. It serves as a precision voltage reference or overvoltage clamp in low-power portable electronics.
For engineers reviewing the BZX84C51LT1 datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage (51 V), tolerance (±5%), thermal resistance (556 °C/W), ESD rating (>16 kV HBM), and SOT-23 footprint compatibility with automated assembly.
Technical Context
This device operates in reverse breakdown mode to maintain stable voltage across its cathode-anode terminals under varying load or supply conditions. Its Zener voltage is specified at three test currents-5 mA (48–54 V), 1 mA (47.6–54 V), and 20 mA (48.1–54.6 V)-with temperature coefficient of +35.7 mV/°C.
The SOT-23 package features pin 1 (anode), pin 2 (no connection), and pin 3 (cathode), with void-free thermosetting plastic case, UL 94 V-0 flammability rating, and maximum soldering temperature of 260°C for 10 seconds.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 48–54 V @ 5 mA - defines regulated output range under standard bias |
| Power Rating | 225 mW on FR-5 board - sets max continuous dissipation without heatsink |
| Zener Impedance | 180 Ω @ 5 mA - indicates voltage regulation stiffness under load transients |
| Reverse Leakage | 100 µA @ 38.3 V - determines minimum holding current for clamping function |
| Temp Coefficient | +35.7 mV/°C - quantifies voltage drift per degree Celsius rise in junction temp |
| Capacitance | 40 pF @ 0 V, 1 MHz - affects high-frequency noise filtering capability |
| ESD Rating | Class 3 (>16 kV HBM) - ensures robustness against handling-induced electrostatic discharge |
Pinout & Package
SOT-23 surface-mount package (Case 318, Style 8), 3-terminal configuration with no internal connection on pin 2. Cathode identified by polarity band. Dimensions: 2.80–3.04 mm length × 1.20–1.40 mm width × 0.99–1.26 mm height.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential side of Zener circuit; reverse-biased during regulation |
| 2 | No Connection | Internally unconnected; must remain floating in PCB layout |
| 3 | Cathode | Connected to higher-potential side; voltage referenced to this terminal during breakdown |
Key Features
| Feature | Design Value |
|---|---|
| Pb-Free Option Available | BZX84C51LT1G variant supports RoHS-compliant manufacturing |
| High ESD Robustness | Class 3 (>16 kV HBM) eliminates need for external ESD protection in handheld designs |
| Optimized for Automated Assembly | SOT-23 footprint and marking enable reliable pick-and-place placement |
| Tight Thermal Performance | 556 °C/W junction-to-ambient resistance allows operation up to +150°C junction temp |
| Stable Low-Current Regulation | Specified Zener voltage at 1 mA enables use in ultra-low-power standby circuits |
Applications
| Smartphone Power Management | USB Port Overvoltage Protection |
|---|---|
Use Scenario: Regulating auxiliary rail voltage in battery-powered smartphone PMIC subsystems. IC Role / Device Role / Timing Role: Zener reference for LDO feedback divider or overvoltage detection threshold. Use Value: 51 V rating provides margin above 3.3/5 V rails while maintaining tight 48–54 V regulation window. | Use Scenario: Clamping transient surges on USB VBUS line during hot-plug events. IC Role / Device Role / Timing Role: Shunt protector that conducts when VBUS exceeds safe operating limit. Use Value: 100 µA leakage at 38.3 V ensures minimal standby current; 180 Ω impedance limits clamping overshoot. |
| IoT Sensor Node Reference | Industrial PLC Input Conditioning |
Use Scenario: Providing stable reference voltage for ADC in battery-operated environmental sensor nodes. IC Role / Device Role / Timing Role: Precision voltage source for analog front-end scaling and calibration. Use Value: +35.7 mV/°C tempco enables predictable drift compensation in firmware algorithms. | Use Scenario: Level-shifting and surge suppression for 24 V DC digital input channels in programmable logic controllers. IC Role / Device Role / Timing Role: Voltage clamp protecting microcontroller GPIO pins from field-induced transients. Use Value: SOT-23 size fits high-density I/O modules; UL 94 V-0 rating meets industrial safety standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5267BLT1 | Same 51 V nominal Zener, but tighter ±2% tolerance and 100 mW rating | Lower power handling limits use in >10 mA bias circuits | Select when higher voltage accuracy outweighs power capability |
| BZX84C51LT3G | Identical electrical specs, Pb-free, supplied in 10,000-piece tape-and-reel | No functional difference; differs only in packaging quantity and RoHS status | Select for volume production requiring Pb-free compliance and larger reels |
Compared with MMBZ5267BLT1, BZX84C51LT1 offers 125% higher power rating (225 mW vs. 100 mW) at the cost of ±5% tolerance; versus BZX84C51LT3G, it shares identical performance but requires separate sourcing for Pb-free compliance and reel size optimization.
Availability
BZX84C51LT1 is available at Aetrix Electronics and suitable for smartphone power management, USB port overvoltage protection, and IoT sensor node reference applications requiring stable component supply and SOT-23 footprint consistency.
Supply support for BZX84C51LT1 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The BZX84CxxxLT1 series is part of onsemi's broad portfolio of discrete Zener regulators designed specifically for space-constrained, low-power voltage reference and clamping functions in portable and high-density PCB environments.
FAQ
What is the Zener voltage tolerance of BZX84C51LT1?
The BZX84C51LT1 has a nominal Zener voltage of 51 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 48 V and 54 V when tested at 5 mA. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official datasheet and applies specifically to the "C" series (standard tolerance) variant of the BZX84 family.
Does BZX84C51LT1 have a connection on pin 2?
No, BZX84C51LT1 has no internal connection on pin 2 - it is electrically isolated and must remain unconnected in the PCB layout. The device uses only pins 1 (anode) and 3 (cathode) for operation, as explicitly stated in the Pinout section on page 3 and Package Dimensions on page 7 of the datasheet.
What is the maximum power dissipation of BZX84C51LT1 on FR-5 board?
The BZX84C51LT1 is rated for 225 mW total power dissipation on FR-5 board at 25°C ambient temperature, with derating of 1.8 mW/°C above that temperature. This value is listed under Maximum Ratings on page 2 and reflects real-world thermal performance on standard PCB material.
Is BZX84C51LT1 RoHS compliant?
The standard BZX84C51LT1 is not inherently Pb-free; however, the BZX84C51LT1G variant is explicitly designated as Pb-free and RoHS compliant per the ordering information on page 2 of the datasheet. Both share identical electrical characteristics, differing only in lead finish and compliance status.
What is the Zener impedance of BZX84C51LT1 at 5 mA?
The BZX84C51LT1 exhibits a maximum Zener impedance (ZZT) of 180 Ω when measured at 5 mA test current and 25°C ambient temperature. This parameter is documented in the Electrical Characteristics table on page 3 and directly impacts regulation stability under dynamic load conditions.
BZX84C51LT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- BZX84CxxxLT1
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 51 V
- Tolerance:
- -
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 180 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 35.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
BZX84C51LT1 FAQ
1.How can I place an order for BZX84C51LT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C51LT1 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 BZX84C51LT1 reliable?
The price and inventory of BZX84C51LT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84C51LT1 is usually 5 days.
3.What payment methods are accepted for BZX84C51LT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C51LT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C51LT1?
BZX84C51LT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C51LT1 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 BZX84C51LT1?
For technical support, including BZX84C51LT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C51LT1 requirements.
6.How does Aetrix verify that BZX84C51LT1 is sourced from the original manufacturer or authorized distributors?
All BZX84C51LT1 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 BZX84C51LT1 meets industry standards.
7.What is the process for return or replacement of BZX84C51LT1?
All BZX84C51LT1 units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C51LT1, 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 BZX84C51LT1 part is unused and in its original packaging.
Return procedure for BZX84C51LT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84C51LT1 Tags
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MMBZ5240B-7-F
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
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BZT52C15-7-F
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
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