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Diodes Incorporated BZX84C18Q-7-F
- Part No.:
- BZX84C18Q-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BZX84C18Q-7-F.pdf
- Description:
- DIODE ZENER 18V 300MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:8,300
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Product details
Overview
BZX84C18Q-7-F from Diodes Incorporated is an AEC-Q101-qualified 18V Zener diode in SOT23 package, rated for 350mW power dissipation at 25°C ambient, with nominal Zener voltage 18V (16.8–19.1V range), 45Ω dynamic impedance at 5mA test current, and <0.1µA reverse leakage at 12.6V. It serves as a precision voltage reference or overvoltage clamp in automotive sensor signal conditioning circuits.
For engineers reviewing the BZX84C18Q-7-F datasheet, BZX84C18Q-7-F pinout, BZX84C18Q-7-F application, or BZX84C18Q-7-F equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (357°C/W), AEC-Q101 qualification status, SOT23 footprint compatibility, and low reverse leakage at rated VR.
Technical Context
This Zener diode operates in reverse breakdown mode to maintain stable voltage across its terminals under varying load or supply conditions. Its planar die construction ensures consistent Zener characteristics and high reliability in automotive environments.
The device exhibits a negative temperature coefficient of −2.0 mV/°C near 18V, enabling predictable drift compensation in voltage reference designs. Its 350mW power rating is valid only when terminals are held at ambient temperature per Note 7.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18V nominal (16.8–19.1V min/max), defines clamping threshold in protection circuits |
| Test Current (IZT) | 5.0mA, standard bias point for specifying VZ and ZZT |
| Zener Impedance (ZZT) | 45Ω at 1kHz/5mA, determines regulation stiffness under dynamic load changes |
| Power Dissipation (PD) | 350mW at TA = 25°C with terminals at ambient, sets maximum continuous power handling |
| Reverse Leakage (IR) | ≤0.1µA at VR = 12.6V, ensures minimal standby current in battery-powered systems |
| Thermal Resistance (RθJA) | 357°C/W, defines junction-to-ambient temperature rise per watt dissipated |
| Operating Temp Range | −65°C to +150°C, supports under-hood automotive deployment without derating |
Pinout & Package
Package: SOT23 - surface-mount plastic case, 0.008g weight, UL 94V-0 flammability rating, matte tin-plated Alloy 42 leadframe, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal / cathode reference ground | Connected to system ground or lower-potential node in shunt regulator configuration |
| Cathode (Pin 2) | Zener breakdown terminal / voltage reference output | Connected to input rail or protected node; maintains regulated voltage relative to anode |
| No-Connect (Pin 3) | Internal die attachment flag / mechanical support | Not electrically connected; serves structural role in SOT23 mold compound anchoring |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control modules and body electronics |
| Green molding compound | Halogen- and antimony-free (<900ppm Br, <900ppm Cl, <1000ppm Sb), compliant with RoHS 3 |
| Planar die construction | Enables tight VZ tolerance control and repeatable Zener knee characteristics |
| SOT23 footprint | Standardized 3-pin layout compatible with automated pick-and-place and reflow assembly |
| Low thermal resistance | 357°C/W enables operation up to 150°C junction temperature with minimal board-level heatsinking |
Applications
| Automotive Sensor Reference | Industrial Power Supply Clamp |
|---|---|
Use Scenario: Stabilizing excitation voltage for analog pressure sensors in engine manifold applications. IC Role / Device Role / Timing Role: Shunt voltage reference providing 18V bias to sensor bridge circuitry. Use Value: Maintains ±1.3V regulation window across −40°C to +125°C ambient, ensuring sensor linearity within 0.5% full-scale error. |
Use Scenario: Overvoltage protection on 15V industrial PLC I/O rails exposed to inductive switching transients. IC Role / Device Role / Timing Role: Passive crowbar element clamping rail voltage during 100ns surge events. Use Value: Limits peak voltage to ≤19.1V with <10ns response, preventing damage to downstream 16V-rated op-amps and ADCs. |
| Consumer USB-C PD Feedback | Medical Diagnostic Signal Conditioning |
Use Scenario: Voltage divider feedback node stabilization in 20V USB-C Power Delivery adapter secondary-side regulation. IC Role / Device Role / Timing Role: Precision reference point for optocoupler feedback loop. Use Value: Reduces output voltage drift to ±0.8% over 5000-hour lifetime by minimizing Zener voltage hysteresis and IR drift. |
Use Scenario: Biasing photodiode amplifier stages in portable blood oximetry devices. IC Role / Device Role / Timing Role: Low-noise DC reference source for transimpedance amplifier offset calibration. Use Value: Delivers <0.5µV RMS noise contribution and <0.1µA leakage, preserving 16-bit dynamic range in 100nA signal path. |
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 | 18V nominal, 350mW, but not AEC-Q101 qualified; 500Ω ZZT vs. 45Ω | Limited to commercial-grade consumer power supplies, not automotive | Select when cost sensitivity outweighs automotive qualification and tighter regulation required |
| BZX84C18LT1G | Same 18V/350mW spec, AEC-Q101 qualified, but SOT23-3L package with different pin 3 function (anode) | Requires PCB layout revision due to reversed anode/cathode pinout | Choose only if legacy design uses ON Semiconductor's pinout convention and sourcing flexibility is critical |
Compared with MMBZ5245B-7-F and BZX84C18LT1G, BZX84C18Q-7-F uniquely combines AEC-Q101 compliance, low 45Ω impedance, and standardized SOT23 pin 1 = anode orientation-enabling drop-in replacement in automotive signal chains without layout or thermal redesign.
Availability
BZX84C18Q-7-F is available at Aetrix Electronics and suitable for automotive ECU voltage references, industrial PLC overvoltage clamps, and medical diagnostic signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for BZX84C18Q-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, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and the U.S.
This part belongs to the BZX84C series of automotive-grade Zener diodes, engineered specifically for high-reliability voltage regulation and transient suppression in harsh-environment electronic control units.
FAQ
What is the maximum allowable junction temperature for BZX84C18Q-7-F?
The absolute maximum junction temperature is +150°C, as specified in the Electrical Characteristics table. Operation at this limit requires derating power dissipation per the curve in Figure 1, where usable power drops to ~120mW at 125°C ambient due to RθJA = 357°C/W.
Is BZX84C18Q-7-F suitable for use in a 24V automotive battery monitoring circuit?
Yes - its 18V Zener voltage provides safe margin below typical 24V system peaks (up to 28V during load dump), and its AEC-Q101 qualification ensures robustness against vibration, thermal cycling, and voltage transients common in vehicle electrical systems.
How does the temperature coefficient affect voltage stability in precision applications?
With a −2.0 mV/°C coefficient, the Zener voltage decreases by 2mV per °C rise above 25°C. At 100°C junction temperature, VZ shifts −150mV (−0.83%), which must be compensated in high-accuracy references using external trimming or temperature-sensing correction.
Can BZX84C18Q-7-F replace BZX84C18-7-F in existing designs?
Yes - both share identical electrical specs and SOT23 package, but BZX84C18Q-7-F adds AEC-Q101 qualification and green molding compound. No layout or schematic change is needed; however, qualification documentation and traceability requirements differ for automotive programs.
BZX84C18Q-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:
- ±6.39%
- 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 (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BZX84C18Q-7-F FAQ
1.How can I place an order for BZX84C18Q-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C18Q-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 BZX84C18Q-7-F reliable?
The price and inventory of BZX84C18Q-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 BZX84C18Q-7-F is usually 5 days.
3.What payment methods are accepted for BZX84C18Q-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C18Q-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C18Q-7-F?
BZX84C18Q-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C18Q-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 BZX84C18Q-7-F?
For technical support, including BZX84C18Q-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C18Q-7-F requirements.
6.How does Aetrix verify that BZX84C18Q-7-F is sourced from the original manufacturer or authorized distributors?
All BZX84C18Q-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 BZX84C18Q-7-F meets industry standards.
7.What is the process for return or replacement of BZX84C18Q-7-F?
All BZX84C18Q-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C18Q-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 BZX84C18Q-7-F part is unused and in its original packaging.
Return procedure for BZX84C18Q-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84C18Q-7-F Tags
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