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Diodes Incorporated BZX84C18W-7-F
- Part No.:
- BZX84C18W-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
BZX84C18W-7-F.pdf
- Description:
- DIODE ZENER 18V 200MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:6,229
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Product details
Overview
BZX84C18W-7-F from Diodes Incorporated is a 18 V, 200 mW surface-mount Zener diode in SOT-323 package, with nominal zener voltage 18 V (min 16.8 V, max 19.1 V at IZT = 5 mA), zener impedance 45 Ω at 5 mA, and reverse current ≤0.1 µA at 12.6 V. It provides precision voltage regulation in low-power biasing and reference circuits.
For engineers reviewing the BZX84C18W-7-F datasheet, BZX84C18W-7-F pinout, BZX84C18W-7-F application, or BZX84C18W-7-F equivalent, key selection criteria include zener voltage tolerance (±6.1%), thermal resistance (625 K/W), low leakage (<0.1 µA), temperature coefficient (+12.4 to +16.0 mV/°C), and RoHS-compliant green molding compound.
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 breakdown characteristics, while the SOT-323 package enables high-density PCB layouts in space-constrained applications.
It delivers regulated output with specified zener voltage (18 V ±6.1%), dynamic impedance (45 Ω at 5 mA), and low temperature coefficient (12.4–16.0 mV/°C). The device is rated for continuous power dissipation of 200 mW at 25°C, derating linearly above 25°C per the published curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V nominal, 16.8–19.1 V range at 5 mA - defines regulation setpoint with ±6.1% tolerance |
| Power Dissipation (PD) | 200 mW at TA = 25°C - limits maximum steady-state energy handling on standard FR4 |
| Zener Impedance (ZZT) | 45 Ω at IZT = 5 mA - determines regulation stiffness against load current changes |
| Reverse Current (IR) | ≤0.1 µA at VR = 12.6 V - ensures minimal quiescent leakage in high-impedance reference nodes |
| Temp Coefficient (αVZ) | +12.4 to +16.0 mV/°C at 5 mA - quantifies voltage drift over operating temperature range |
| Thermal Resistance (RθJA) | 625 K/W - indicates junction-to-ambient rise per watt; requires thermal pad layout per AP02001 |
Pinout & Package
Package: SOT-323 - ultra-small surface-mount plastic case (2.0–2.2 mm length, 1.15–1.35 mm width, 0.25–0.40 mm thickness), UL 94V-0 rated, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal / cathode reference | Connected to lower-potential node in reverse-bias configuration; polarity marked on top view |
| Cathode (Pin 2) | Zener breakdown terminal | Connected to higher-potential node; carries regulated voltage when reverse biased |
| Case / Heat Sink (Pin 3) | Non-electrical mechanical termination | Exposed leadframe tie-bar; not electrically connected - serves only mechanical anchoring |
Key Features
| Feature | Design Value |
|---|---|
| Planar die construction | Ensures repeatable breakdown voltage and low parameter spread across production lots |
| Green molding compound | Halogen-free, RoHS-compliant encapsulation meeting UL 94V-0 flammability rating |
| SOT-323 footprint | Enables <1.0 mm² board area usage - suitable for wearables, IoT sensors, and portable power rails |
| Lead-free matte tin plating | Compatible with Pb-free reflow profiles and eliminates post-solder cleaning requirements |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Providing stable 18 V reference for ADC voltage dividers or op-amp bias networks in battery-powered instrumentation. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to fix reference node potential. Use Value: Delivers ±6.1% voltage accuracy and <0.1 µA leakage, minimizing error contribution in precision analog front-ends. | Use Scenario: Protecting microcontroller GPIO pins from transient overvoltage events exceeding 18 V. IC Role / Device Role / Timing Role: Shunt clamp absorbing surge energy by entering controlled breakdown. Use Value: Limits clamped voltage to ≤19.1 V with 45 Ω dynamic impedance, reducing stress on downstream logic inputs. |
| LED Current Regulation | Signal Level Translation |
Use Scenario: Setting constant current for indicator LEDs in automotive dashboard modules using series resistor + Zener bias. IC Role / Device Role / Timing Role: Voltage reference defining emitter/base bias point in simple transistor current source. Use Value: Maintains LED brightness stability across 25–85°C ambient due to predictable +12.4–16.0 mV/°C tempco. | Use Scenario: Translating 3.3 V logic signals to 18 V interface levels for industrial sensor excitation circuits. IC Role / Device Role / Timing Role: Clamping reference node to fixed 18 V rail while allowing AC-coupled signal swing. Use Value: Provides clean DC offset with <0.1 µA leakage, avoiding loading of high-impedance source signals. |
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 | Zener voltage 18 V (17.1–18.9 V), 350 mW PD, SOT-23 package, 20 Ω ZZT | Higher power rating and lower impedance, but larger footprint and different thermal profile | Select when higher surge energy handling or tighter regulation is required and board space permits SOT-23 |
| 1SMA5926BT3G | Zener voltage 18 V (16.9–19.1 V), 1.5 W PD, SMA package, 10 Ω ZZT | Substantially higher power capability and lower impedance, but 3× larger size and higher cost | Choose for high-reliability industrial clamping where 200 mW is insufficient |
Compared with MMBZ5245B-7-F and 1SMA5926BT3G, BZX84C18W-7-F offers optimal balance of miniaturization (SOT-323), low leakage (<0.1 µA), and adequate regulation for space-constrained, low-power reference and clamp roles - without over-specifying power or footprint.
Availability
BZX84C18W-7-F is available at Aetrix Electronics and suitable for precision voltage reference, overvoltage protection, LED biasing, and signal level translation requiring stable component supply in high-volume consumer, industrial, and automotive electronics.
Supply support for BZX84C18W-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, industry-standard components for power management, signal integrity, and protection.
The BZX84C series belongs to Diodes' general-purpose Zener diode product line, designed specifically for compact, low-power voltage regulation and clamping in cost-sensitive, space-constrained applications.
FAQ
What is the maximum reverse voltage before breakdown for BZX84C18W-7-F?
The device exhibits sharp reverse breakdown at nominal 18 V, with guaranteed range 16.8–19.1 V at test current IZT = 5 mA. Below 12.6 V, reverse current remains ≤0.1 µA - confirming no significant conduction prior to the specified knee region.
Can BZX84C18W-7-F be used in place of a 15 V Zener diode?
No - it is not interchangeable with 15 V Zeners such as BZX84C15W. Its 18 V nominal voltage and ±6.1% tolerance (16.8–19.1 V) exceed the 15 V specification (13.8–15.6 V), risking overvoltage in circuits dependent on precise 15 V regulation or clamping.
Is the SOT-323 package compatible with standard reflow soldering profiles?
Yes - the device uses lead-free matte tin plating and is qualified for Pb-free reflow per J-STD-020D. Its moisture sensitivity level is 1, eliminating bake requirements; recommended peak temperature is ≤260°C with ≤60 sec above 217°C for SnPb or Pb-free processes.
Does BZX84C18W-7-F have a specified capacitance value?
No specific capacitance is listed in the DS30066 datasheet for this variant. However, Figure 4 shows typical total capacitance for 18 V Zeners is ~15 pF at VR = 1 V and ~10 pF at VR = 2 V, measured at 1 MHz - relevant for high-frequency noise filtering applications.
BZX84C18W-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±6%
- Power - Max:
- 200 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 ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BZX84C18W-7-F FAQ
1.How can I place an order for BZX84C18W-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX84C18W-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 BZX84C18W-7-F reliable?
The price and inventory of BZX84C18W-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 BZX84C18W-7-F is usually 5 days.
3.What payment methods are accepted for BZX84C18W-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX84C18W-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX84C18W-7-F?
BZX84C18W-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX84C18W-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 BZX84C18W-7-F?
For technical support, including BZX84C18W-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX84C18W-7-F requirements.
6.How does Aetrix verify that BZX84C18W-7-F is sourced from the original manufacturer or authorized distributors?
All BZX84C18W-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 BZX84C18W-7-F meets industry standards.
7.What is the process for return or replacement of BZX84C18W-7-F?
All BZX84C18W-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BZX84C18W-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 BZX84C18W-7-F part is unused and in its original packaging.
Return procedure for BZX84C18W-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX84C18W-7-F Tags
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MMBZ5240B-7-F
Diodes Incorporated
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Diodes Incorporated
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MMSZ5231B-7-F
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BZT52C15S-7-F
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