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onsemi SZBZX84C18LT3
- Part No.:
- SZBZX84C18LT3
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SZBZX84C18LT3.pdf
- Description:
- DIODE ZENER 18V 225MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:120,000
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Product details
Overview
SZBZX84C18LT3 from onsemi is a 18 V, ±5% tolerance Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board at 25°C, with 45 Ω dynamic impedance at 5 mA test current and 12.6 mV/°C temperature coefficient - used for precision voltage reference and overvoltage protection in portable power rails.
For engineers reviewing the SZBZX84C18LT3 datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5%), thermal coefficient (12.6 mV/°C), leakage current (≤50 nA at 14.4 V), SOT-23 footprint compatibility, and AEC-Q101 qualification status.
Technical Context
This device operates as a two-terminal voltage reference diode with cathode-anode polarity, designed for reverse-biased regulation. Its Zener breakdown occurs at nominal 18 V with tight 16.8–19.1 V min–max range at 5 mA, and exhibits low dynamic impedance (45 Ω) ensuring stable regulation under varying load currents.
It features Class 3 ESD robustness (>16 kV HBM), Pb-free SOT-23 packaging compliant with UL 94 V-0 flammability rating, and is qualified to AEC-Q101 for automotive-grade reliability - supporting operation across −65°C to +150°C junction temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V nominal, 16.8–19.1 V min–max at IZT = 5 mA - defines regulated output voltage window under standard test conditions |
| Power Dissipation | 225 mW on FR-5 board at 25°C - sets maximum continuous power handling before thermal derating begins |
| Zener Impedance (ZZT) | 45 Ω max at IZT = 5 mA - determines regulation stiffness and output voltage variation under load transients |
| Reverse Leakage Current | ≤50 nA at VR = 14.4 V - ensures minimal quiescent current draw in standby or high-impedance bias networks |
| Temperature Coefficient | +12.6 mV/°C at IZT = 5 mA - quantifies voltage drift per degree Celsius, critical for temperature-stable references |
| Capacitance | 100 pF max at VR = 0 V, f = 1 MHz - impacts high-frequency noise filtering and signal integrity in bypass applications |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - enables direct integration into handheld and exposed I/O circuits without external protection |
Pinout & Package
SOT-23 plastic surface-mount package (Case 318, Style 8), void-free thermosetting construction with corrosion-resistant finish, 260°C soldering tolerance for 10 seconds, cathode indicated by band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node in reverse-bias configuration; forms current entry path during Zener conduction |
| 2 | No Connection | Internally unconnected terminal - must remain floating; no PCB trace or pad required |
| 3 | Cathode | Connected to higher-potential node; marked by polarity band; carries regulated output voltage when reverse-biased |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 Qualified | Validated for automotive applications including engine control modules and infotainment power supplies |
| 225 mW FR-5 Power Rating | Enables compact voltage clamping in space-constrained layouts without forced airflow or heatsinking |
| ±5% Zener Tolerance | Supports accurate 18 V reference generation without post-production trimming in cost-sensitive designs |
| Class 3 ESD Robustness | Eliminates need for discrete ESD protection in battery-powered interfaces and USB-adjacent circuits |
| Pb-Free SOT-23 Package | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 requirements |
Applications
| Portable Device Power Rail Clamp | Automotive Sensor Reference |
|---|---|
|
Use Scenario: Clamping 18 V supply rail in Bluetooth headset charging circuit against transient overvoltage events. IC Role / Device Role / Timing Role: Two-terminal shunt regulator providing passive overvoltage protection without control logic or feedback loop. Use Value: Limits rail excursion to ≤19.1 V during 100 ns ESD pulses, preventing damage to LDOs and audio codecs downstream. |
Use Scenario: Providing stable 18 V reference for analog front-end of tire pressure monitoring system (TPMS) sensor. IC Role / Device Role / Timing Role: Precision voltage reference source for ADC biasing and sensor excitation in low-power automotive sensors. Use Value: Maintains <±0.5% output stability over −40°C to +125°C due to +12.6 mV/°C TC and AEC-Q101 qualification. |
| Industrial PLC Input Protection | Medical Wearable Battery Monitor |
|
Use Scenario: Protecting 24 V digital input channel of programmable logic controller against field-wiring surges. IC Role / Device Role / Timing Role: Fast-response shunt clamp absorbing surge energy while holding input voltage below 19.1 V threshold. Use Value: Withstands repeated 1 kV/500 Ω surge events per IEC 61000-4-5 due to 225 mW rating and low ZZT. |
Use Scenario: Regulating reference voltage for fuel gauge IC in rechargeable smart patch monitor operating from Li-ion cell. IC Role / Device Role / Timing Role: Low-leakage (≤50 nA) Zener reference enabling >10-year shelf life and microamp-level sleep current budgets. Use Value: Enables 0.1% full-scale accuracy in coulomb counting despite wide temperature swings in body-worn environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84C18LT3 | Same 18 V nominal, ±5% tolerance, SOT-23, but non-automotive grade; no AEC-Q101 qualification | Lacks automotive reliability validation; suitable only for commercial-grade consumer electronics | Choose when cost sensitivity outweighs automotive compliance requirements |
| SZBZX84C18LT3G | Identical electrical specs and AEC-Q101 qualification; Pb-free suffix confirms RoHS-compliant plating | Same automotive use cases; differs only in lead finish and JEDEC moisture sensitivity level | Select when Pb-free assembly process or MSL-1 reflow profile is mandatory |
Compared with SZBZX84C18LT3, BZX84C18LT3 offers identical regulation performance at lower cost but excludes automotive qualification, while SZBZX84C18LT3G adds Pb-free compliance without altering voltage or thermal behavior - enabling drop-in substitution where environmental standards apply.
Availability
SZBZX84C18LT3 is available at Aetrix Electronics and suitable for automotive sensor modules, portable medical devices, industrial PLC inputs, and battery management systems requiring stable component supply with AEC-Q101 assurance and long-term lifecycle support.
Supply support for SZBZX84C18LT3 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 silicon solutions for automotive, industrial, cloud, and IoT applications.
SZBZX84C18LT3 belongs to the BZX84CxxxLT1 family of Zener regulators, engineered specifically for high-density, low-power voltage reference and overvoltage protection in automotive and portable electronics.
FAQ
What is the Zener voltage tolerance of SZBZX84C18LT3?
The SZBZX84C18LT3 has a nominal Zener voltage of 18 V with a tolerance of ±5%, resulting in a guaranteed regulation range of 16.8 V to 19.1 V at 5 mA test current. This tolerance is specified in the Electrical Characteristics table on page 3 of the official datasheet and applies across the full operating temperature range.
Is SZBZX84C18LT3 qualified for automotive applications?
Yes, SZBZX84C18LT3 is AEC-Q101 qualified and PPAP capable, as explicitly stated in the Features section of the datasheet. This qualification validates its reliability for automotive use cases including engine control units, ADAS sensors, and infotainment power supplies under extended temperature and vibration stress conditions.
What is the maximum power dissipation of SZBZX84C18LT3 on FR-5 board?
SZBZX84C18LT3 is rated for 225 mW total power dissipation on FR-5 board at 25°C ambient temperature, with thermal derating of 1.8 mW/°C above that point. This value is defined in the Maximum Ratings table and reflects real-world PCB thermal performance under standard JEDEC test conditions.
Does SZBZX84C18LT3 have a no-connect pin, and how should it be handled on PCB?
Yes, pin 2 of SZBZX84C18LT3 is internally not connected and must remain unconnected on the PCB layout. The datasheet's Marking Diagram and Electrical Characteristics section confirm pinout as 1-Anode, 2-No Connection, 3-Cathode - routing or soldering to pin 2 may cause assembly defects or functional failure.
What is the reverse leakage current specification for SZBZX84C18LT3 at 14.4 V?
The reverse leakage current for SZBZX84C18LT3 is specified as ≤50 nA at VR = 14.4 V (80% of nominal Zener voltage), per the Electrical Characteristics table on page 3. This low leakage supports ultra-low-power applications such as battery-backed memory retention and always-on sensor bias networks.
SZBZX84C18LT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±6%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 12.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
SZBZX84C18LT3 FAQ
1.How can I place an order for SZBZX84C18LT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for SZBZX84C18LT3 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 SZBZX84C18LT3 reliable?
The price and inventory of SZBZX84C18LT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZBZX84C18LT3 is usually 5 days.
3.What payment methods are accepted for SZBZX84C18LT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZBZX84C18LT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZBZX84C18LT3?
SZBZX84C18LT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZBZX84C18LT3 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 SZBZX84C18LT3?
For technical support, including SZBZX84C18LT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZBZX84C18LT3 requirements.
6.How does Aetrix verify that SZBZX84C18LT3 is sourced from the original manufacturer or authorized distributors?
All SZBZX84C18LT3 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 SZBZX84C18LT3 meets industry standards.
7.What is the process for return or replacement of SZBZX84C18LT3?
All SZBZX84C18LT3 units undergo pre-shipment inspection (PSI). If there is an issue with SZBZX84C18LT3, 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 SZBZX84C18LT3 part is unused and in its original packaging.
Return procedure for SZBZX84C18LT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZBZX84C18LT3 Tags
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