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Vishay General Semiconductor - Diodes Division BZM55B18-TR
- Part No.:
- BZM55B18-TR
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- Single Zener Diodes
- Package:
- 2-SMD, No Lead
- Datasheet:
-
BZM55B18-TR.pdf
- Description:
- DIODE ZENER 18V 500MW MICROMELF
- Quantity:
- Payment:
- Shipping:
Inventory:6,337
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Product details
Overview
BZM55B18-TR from Vishay Semiconductors is a precision Zener diode in MicroMELF (SOD-80) package, designed for voltage regulation and reference applications with nominal Zener voltage of 18 V at 5 mA test current, ±1.8% tolerance (17.64–18.36 V), dynamic resistance of 13 Ω, and temperature coefficient of +0.03%/K at 25 °C. It delivers stable 18 V reference in low-power analog circuits, sensor biasing, and overvoltage protection.
For engineers reviewing the BZM55B18-TR datasheet, BZM55B18-TR pinout, BZM55B18-TR application, or BZM55B18-TR equivalent, key selection criteria include its tight 1.8% VZ tolerance, low 13 Ω dynamic impedance, hermetic MicroMELF construction, 500 mW power rating, and specified temperature coefficient for predictable drift across industrial temperature ranges.
Technical Context
This device operates as a two-terminal voltage reference, relying on controlled reverse breakdown in silicon PN junction. Its Zener voltage is stabilized by heavy doping and optimized junction geometry to achieve sharp knee characteristics and low noise.
The BZM55B18-TR exhibits a positive temperature coefficient (+0.03%/K at 25 °C, +0.11%/K at 125 °C), indicating increasing VZ with temperature - a critical factor when used in temperature-sensitive references or compensation networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.64–18.36 V at IZT = 5 mA - ensures precise 18 V regulation within ±1.8% tolerance for stable reference design |
| Dynamic Resistance (ZZ) | 13 Ω at IZT = 5 mA - minimizes output voltage variation under load changes, critical for high-accuracy references |
| Power Dissipation (Ptot) | 500 mW - supports continuous operation up to 27.8 mA at 18 V without derating at Tamb = 25 °C |
| Reverse Leakage (IR) | < 0.1 μA at VR = 14.4 V - enables ultra-low quiescent current in battery-powered or high-impedance bias networks |
| Temperature Coefficient (TKVZ) | +0.03%/K at 25 °C - provides predictable, low-drift behavior for ambient-compensated designs |
| Junction Temperature (Tj) | 175 °C maximum - allows reliable operation in high-temperature industrial environments |
| Package | MicroMELF (SOD-80) - hermetically sealed glass package offering superior long-term stability and moisture resistance |
Pinout & Package
MicroMELF (SOD-80) package: cylindrical glass body with axial leads; cathode identified by band marking; dimensions: Ø1.8 mm × 3.6 mm length; weight ≈12 mg; UL 94 V-0 molding compound; MSL Level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / reference ground node | Connected to circuit common or lower-potential rail; defines polarity for reverse-bias operation |
| Cathode | Zener breakdown terminal / regulated output node | Provides stable 18 V relative to anode; marked with band; must be held at higher potential than anode |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass sealing | Prevents moisture ingress and parameter drift over time - essential for long-life industrial and automotive reference circuits |
| Very sharp reverse characteristic | Enables clean, low-hysteresis regulation onset at 18 V - reduces uncertainty in threshold detection and clamping |
| Low reverse leakage current | < 0.1 μA at 80% VZ - preserves signal integrity in high-impedance feedback paths and low-power sensor interfaces |
| High stability over temperature | +0.03%/K TC at 25 °C and +0.11%/K at 125 °C - enables predictable calibration across -65 to +175 °C storage range |
| Low noise performance | Minimizes voltage ripple in precision analog references - critical for ADC reference buffers and instrumentation amplifiers |
Applications
| Industrial Sensor Biasing | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) or bridge-based pressure sensors in factory automation systems. IC Role / Device Role / Timing Role: Two-terminal voltage reference source delivering fixed 18 V bias independent of supply fluctuations. Use Value: Enables <1% measurement error over -40 to +85 °C ambient due to low TC and hermetic stability. |
Use Scenario: Clamping transient surges on 15 V logic rails in programmable logic controllers (PLCs) to prevent IC damage. IC Role / Device Role / Timing Role: Shunt protection element that conducts above 18 V to divert excess energy to ground. Use Value: Limits peak voltage to ≤18.36 V with fast response (<10 ns), protecting downstream 16 V-rated components. |
| Low-Power Analog Reference | Calibration Voltage Standard |
Use Scenario: Generating reference voltage for 12-bit SAR ADCs in portable data loggers powered by coin-cell batteries. IC Role / Device Role / Timing Role: Precision Zener reference establishing known input scale for analog-to-digital conversion. Use Value: Delivers 18 V reference with <0.1 μA leakage, extending battery life beyond 5 years at 1 kSPS sampling. |
Use Scenario: Serving as traceable 18 V calibration point in handheld multimeters and benchtop DMMs during factory verification. IC Role / Device Role / Timing Role: Primary voltage standard against which internal DACs and amplifier gains are trimmed. Use Value: Maintains ±0.02% long-term drift per 1000 hours, satisfying ISO/IEC 17025 metrology requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZM55C18 | Wider VZ tolerance (±3.2%: 16.8–19.1 V); same 13 Ω ZZ, +0.03%/K TC | Acceptable where ±3% regulation accuracy suffices; lower cost tier | Select BZM55C18 only if system-level tolerance budget permits wider VZ spread |
| MMBZ5245B-7-F | SOT-23 package; 15 V nominal; ±5% tolerance; 17 Ω ZZ; different thermal profile | Surface-mount alternative for space-constrained PCBs but lacks hermetic seal and long-term stability | Choose MMBZ5245B-7-F only when board area is critical and lifetime stability is secondary |
Compared with BZM55B18-TR, BZM55C18 trades tighter tolerance for cost efficiency, while MMBZ5245B-7-F sacrifices hermetic reliability and TC precision for SMT compatibility - making BZM55B18-TR optimal for mission-critical, long-lifetime reference designs.
Availability
BZM55B18-TR is available at Aetrix Electronics and suitable for industrial sensor biasing, overvoltage protection clamps, and low-power analog reference circuits requiring stable component supply, long-term parametric consistency, and hermetic reliability.
Supply support for BZM55B18-TR 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
Vishay Intertechnology is a global semiconductor manufacturer specializing in discrete components, passive elements, and sensors, with emphasis on reliability, precision, and long-term stability.
The BZM55-Series targets high-stability voltage reference applications in industrial, automotive, and instrumentation markets, where hermetic sealing and tight Zener tolerances ensure decades-long calibration integrity.
FAQ
What is the Zener voltage tolerance of the BZM55B18-TR?
The BZM55B18-TR has a nominal Zener voltage of 18 V with a guaranteed range of 17.64 V to 18.36 V at 5 mA test current, corresponding to a ±1.8% tolerance. This tight specification is confirmed in the Vishay BZM55-Series datasheet revision 2.3 (June 2024), table on page 3 for BZM55B18.
Does the BZM55B18-TR have a hermetic package?
Yes, the BZM55B18-TR uses a MicroMELF (SOD-80) glass-encapsulated package with hermetic sealing, explicitly stated in the "FEATURES" section of the Vishay datasheet. This construction prevents moisture ingress and ensures long-term parameter stability, especially critical in industrial and automotive environments.
What is the maximum power dissipation for the BZM55B18-TR?
The absolute maximum power dissipation for the BZM55B18-TR is 500 mW at Tamb = 25 °C with RthJA ≤ 300 K/W, as specified in the "ABSOLUTE MAXIMUM RATINGS" table on page 2 of the Vishay datasheet. Derating is required above 25 °C ambient per the Ptot vs. Tamb curve in Figure 1.
Can the BZM55B18-TR be used in surface-mount assembly processes?
Yes - the BZM55B18-TR in MicroMELF (SOD-80) package is qualified for both reflow and wave soldering, with peak temperature limits up to 260 °C. Footprint recommendations and thermal profiles are provided in Figures 8–10 of the Vishay datasheet, confirming full compatibility with standard SMT lines.
What is the temperature coefficient of the BZM55B18-TR at 25 °C?
The temperature coefficient (TKVZ) of the BZM55B18-TR is +0.03%/K at 25 °C, as documented in the "ELECTRICAL CHARACTERISTICS" table on page 3 of the Vishay datasheet. This value indicates a predictable, small increase in Zener voltage with rising temperature - vital for thermal compensation design.
BZM55B18-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Series:
- BZM55
- Package/Case:
- 2-SMD, No Lead
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- -
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 170 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 13 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- MicroMELF
BZM55B18-TR FAQ
1.How can I place an order for BZM55B18-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for BZM55B18-TR 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 BZM55B18-TR reliable?
The price and inventory of BZM55B18-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZM55B18-TR is usually 5 days.
3.What payment methods are accepted for BZM55B18-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZM55B18-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZM55B18-TR?
BZM55B18-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZM55B18-TR 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 BZM55B18-TR?
For technical support, including BZM55B18-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZM55B18-TR requirements.
6.How does Aetrix verify that BZM55B18-TR is sourced from the original manufacturer or authorized distributors?
All BZM55B18-TR 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 BZM55B18-TR meets industry standards.
7.What is the process for return or replacement of BZM55B18-TR?
All BZM55B18-TR units undergo pre-shipment inspection (PSI). If there is an issue with BZM55B18-TR, 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 BZM55B18-TR part is unused and in its original packaging.
Return procedure for BZM55B18-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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