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Diodes Incorporated BZX84C18-7-F
- Part No.:
- BZX84C18-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84C18-7-F.pdf
- Description:
- DIODE ZENER 18V 300MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:16,498
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Product details
Overview
BZX84C18-7-F from Diodes Incorporated is a 350mW surface-mount Zener diode with a nominal zener voltage of 18V (16.8–19.1V range), 45Ω maximum zener impedance at 5mA test current, and ±0.1µA maximum reverse leakage at 12.6V. It operates within –65°C to +150°C and is used for precision voltage regulation and overvoltage protection in low-power DC rails.
For engineers reviewing the BZX84C18-7-F datasheet, BZX84C18-7-F pinout, BZX84C18-7-F application, or BZX84C18-7-F equivalent, key selection criteria include zener voltage tolerance, dynamic impedance at rated test current, thermal resistance (357°C/W), power derating above 25°C, and SOT23 package compatibility with automated pick-and-place assembly.
Technical Context
This device employs planar die construction for stable breakdown characteristics and low temperature coefficient (±0.4 mV/°C typical near 18V). Its 350mW power rating is valid only when terminals are held at ambient temperature; derating begins above 25°C per Figure 1.
The SOT23 package enables high-density PCB layouts and supports reflow soldering per J-STD-020 Level 1 moisture sensitivity. Terminal plating uses matte tin over Alloy 42 leadframe, ensuring MIL-STD-202-compliant solderability without lead or halogen additives.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18V nominal, 16.8–19.1V min/max at IZT = 5mA - defines regulated output voltage under design load |
| Zener Impedance (ZZT) | 45Ω max at 5mA - determines regulation stiffness and output ripple suppression capability |
| Power Dissipation (PD) | 350mW at TA = 25°C - sets maximum continuous DC power handling before thermal shutdown |
| Thermal Resistance (RθJA) | 357°C/W - quantifies junction-to-ambient temperature rise per watt, critical for board-level thermal design |
| Reverse Leakage (IR) | 0.1µA max at VR = 12.6V - ensures minimal quiescent current in standby or sensing circuits |
| Operating Temperature | –65°C to +150°C - supports industrial and automotive under-hood applications without derating |
Pinout & Package
Package: SOT23 - surface-mount plastic case with 3 terminals, UL 94V-0 flammability rating, 0.008g weight, and matte tin-plated Alloy 42 leadframe.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction path / cathode reference | Connected to lower-potential node; reverse-biased during regulation |
| Cathode (Pin 2) | Zener breakdown terminal | Connected to higher-potential rail; clamps voltage to VZ when reverse biased |
| No-Connect (Pin 3) | Internal die attach flag / mechanical support | Not electrically connected; serves as heatsink tab and mechanical anchor in SOT23 outline |
Key Features
| Feature | Design Value |
|---|---|
| Planar die construction | Enables tight VZ tolerance and repeatable breakdown behavior across temperature and life |
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness |
| Halogen- and antimony-free "Green" compound | Meets <900ppm Br, <900ppm Cl, <1000ppm Sb - satisfies strict environmental compliance requirements |
| SOT23 footprint compatibility | Matches JEDEC TO-236AB standard - enables drop-in replacement and automated assembly without redesign |
Applications
| Power Supply Voltage Reference | Overvoltage Clamp Circuit |
|---|---|
Use Scenario: Stabilizing feedback node in adjustable LDOs or switching regulator error amplifiers. IC Role / Device Role / Timing Role: Provides precise, temperature-stable reference voltage for control loop stability. Use Value: 45Ω ZZT minimizes regulation error under varying load currents; ±0.1µA IR avoids loading sensitive op-amp inputs. | Use Scenario: Protecting microcontroller I/O pins from transient surges on 12V–24V industrial bus lines. IC Role / Device Role / Timing Role: Shunts excess energy to ground when line voltage exceeds 18V threshold. Use Value: 350mW PD sustains short-duration transients; 357°C/W RθJA allows safe operation on standard FR-4 without heatsinking. |
| Temperature-Compensated Sensor Bias | Low-Power Battery Monitor Threshold |
Use Scenario: Biasing silicon temperature sensors in HVAC control modules operating from –40°C to +125°C. IC Role / Device Role / Timing Role: Supplies stable excitation current while compensating for sensor nonlinearity via matched TC. Use Value: Low ±0.4 mV/°C tempco near 18V reduces drift-induced measurement error across full operating range. | Use Scenario: Detecting end-of-charge or low-battery condition in portable medical devices using single-cell Li-ion (3.0–4.2V) or dual-cell alkaline (1.8–3.2V) packs. IC Role / Device Role / Timing Role: Acts as comparator reference in discrete voltage monitor circuit with hysteresis. Use Value: Tight 16.8–19.1V VZ window enables accurate threshold setting; SOT23 size fits space-constrained battery compartments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5245B-7-F | 20V nominal, 350mW, 23Ω ZZT, same SOT23 package | Higher VZ and lower impedance suit tighter regulation needs but require recalibration of reference divider | Select when 20V regulation with improved stiffness outweighs need for exact 18V match |
| BZX84-C18,115 | Same 18V spec, 300mW PD, 50Ω ZZT, SOT23, Nexperia | Lower power rating and higher impedance reduce margin in high-current clamp scenarios | Prefer for cost-sensitive consumer designs where 300mW derating and 50Ω ZZT remain acceptable |
Compared with MMBZ5245B-7-F and BZX84-C18,115, the BZX84C18-7-F delivers optimal balance of 18V accuracy, 45Ω regulation stiffness, and AEC-Q101 qualification-making it preferred for automotive and industrial voltage reference and clamp functions requiring traceable reliability.
Availability
BZX84C18-7-F is available at Aetrix Electronics and suitable for voltage reference design, overvoltage protection, sensor biasing, and low-power battery monitoring requiring stable component supply and RoHS/Green compliance.
Supply support for BZX84C18-7-F 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, application-optimized components for automotive, industrial, and computing markets.
The BZX84 series belongs to Diodes' precision Zener diode product line, engineered for stable voltage regulation and transient suppression in space-constrained, thermally demanding environments.
FAQ
What is the maximum reverse voltage (VR) that BZX84C18-7-F can withstand before breakdown?
The BZX84C18-7-F has a nominal zener voltage of 18V with a guaranteed range of 16.8V to 19.1V at 5mA test current. Its reverse breakdown is specified at VZ; no separate VR rating exists because it is designed to operate in controlled reverse breakdown. The device maintains <0.1µA leakage up to 12.6V, confirming stable blocking below the knee voltage.
Is BZX84C18-7-F suitable for use in automotive applications?
Yes - BZX84C18-7-F is explicitly qualified to AEC-Q101 standards, covering stress tests for temperature cycling, high-temperature reverse bias, and electrostatic discharge. Its –65°C to +150°C operating range, green molding compound, and SOT23 package meet automotive PCB assembly and under-hood environmental requirements.
How does the SOT23 package affect thermal performance in continuous operation?
In free-air conditions with terminals held at ambient temperature, the SOT23 package delivers 357°C/W junction-to-ambient thermal resistance. When mounted on FR-4 with recommended pad layout, RθJA improves to 417°C/W. Derating begins linearly above 25°C: at 85°C ambient, maximum dissipation drops to ~210mW per Figure 1.
Can BZX84C18-7-F replace older BZX84C18 variants with different suffixes?
Yes - the "-7-F" suffix denotes 3,000-piece tape-and-reel packaging and lead-free/RoHS/Green compliance. Electrically and mechanically identical to other BZX84C18 variants (e.g., -13-F, Q-7-F), it differs only in packaging format and compliance level, making it a direct replacement in both standard and automotive designs.
BZX84C18-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±6%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 12.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BZX84C18-7-F FAQ
1.How can I place an order for BZX84C18-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C18-7-F 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 BZX84C18-7-F reliable?
The price and inventory of BZX84C18-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX84C18-7-F is usually 5 days.
3.What payment methods are accepted for BZX84C18-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C18-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C18-7-F?
BZX84C18-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C18-7-F 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 BZX84C18-7-F?
For technical support, including BZX84C18-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C18-7-F requirements.
6.How does Aetrix verify that BZX84C18-7-F is sourced from the original manufacturer or authorized distributors?
All BZX84C18-7-F 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 BZX84C18-7-F meets industry standards.
7.What is the process for return or replacement of BZX84C18-7-F?
All BZX84C18-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C18-7-F, 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 BZX84C18-7-F part is unused and in its original packaging.
Return procedure for BZX84C18-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84C18-7-F Tags
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