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Taiwan Semiconductor Corporation BZY55B18 RBG
- Part No.:
- BZY55B18 RBG
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Zener Diodes
- Package:
- 0805 (2012 Metric)
- Datasheet:
-
BZY55B18 RBG.pdf
- Description:
- DIODE ZENER 18V 500MW 805
- Quantity:
- Payment:
- Shipping:
Inventory:8,066
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Product details
Overview
BZY55B18 RBG from Taiwan Semiconductor is a surface-mount 18 V ±2% Zener diode in 0805 ceramic package, rated for 500 mW power dissipation and 5 mA test current, with 50 Ω zener impedance at IZT and 0.1 µA leakage at 13.0 V reverse bias - used for precision voltage reference in DC/DC converters and LED lighting regulation.
For engineers reviewing the BZY55B18 RBG datasheet, BZY55B18 RBG pinout, BZY55B18 RBG application, or BZY55B18 RBG equivalent, key selection criteria include verified 18.0 V nominal Zener voltage (min 17.64 V / max 18.36 V), 500 mW thermal limit, 0805 footprint compatibility, and RoHS-compliant ceramic construction suitable for high-reliability board-level stabilization.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable voltage under varying load conditions, with tight ±2% tolerance and low dynamic impedance (50 Ω at 5 mA) ensuring minimal output variation across current changes. Its 0805 ceramic package provides mechanical robustness and meets JESD201 Class 1A whisker resistance.
The device supports operation from −55°C to +150°C junction temperature, with 300°C/W junction-to-ambient thermal resistance limiting continuous power handling at elevated ambient temperatures. Leakage current remains ≤0.1 µA up to 13.0 V reverse bias, enabling low-power standby reference functionality.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.64–18.36 V @ 5 mA - ensures stable 18 V reference within ±2% tolerance for feedback loops |
| Power Dissipation (PD) | 500 mW - defines maximum steady-state power before thermal derating begins |
| Zener Impedance (ZZT) | 50 Ω @ IZT = 5 mA - determines output voltage ripple sensitivity to load current transients |
| Leakage Current (IR) | ≤0.1 µA @ VR = 13.0 V - enables ultra-low quiescent current in battery-backed reference circuits |
| Forward Voltage (VF) | 1.5 V @ IF = 10 mA - relevant for polarity-check or ESD protection use cases in forward bias |
| Junction Temperature Range | −55°C to +150°C - supports operation in automotive under-hood and industrial control environments |
Pinout & Package
Package: 0805 (2.00 mm × 1.25 mm × 0.75 mm ceramic SMD), cathode indicated by band on top surface; no internal terminals - two-terminal device with anode and cathode pads aligned to standard 0805 land pattern.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pad A) | Current entry point in forward bias; reference ground node in reverse-bias regulator | Connected to circuit ground or lower-potential rail when used as shunt regulator |
| Cathode (Pad K) | Current exit point in forward bias; regulated output node in reverse bias | Connected to input supply rail and feedback node - maintains fixed voltage relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance | Enables direct replacement without recalibration in voltage-reference designs requiring <2.5% accuracy |
| Moisture Sensitivity Level 1 | Eliminates bake requirement prior to reflow - compatible with standard SMT assembly lines |
| JESD201 Class 1A whisker resistance | Prevents tin whisker growth in long-life industrial applications operating >10 years |
| UL 94HB molding compound | Meets basic flammability requirements for consumer and industrial PCBs without halogen-free premium cost |
Applications
| LED Lighting Regulation | On-board DC/DC Converter Reference |
|---|---|
Use Scenario: Stabilizing bias voltage for constant-current LED driver ICs in smart luminaires. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 18 V feedback to PWM controller error amplifier. Use Value: Maintains ±2% LED current accuracy over temperature and line variations due to tight VZ tolerance and low ZZT. | Use Scenario: Setting output voltage of isolated flyback or buck converter in telecom power modules. IC Role / Device Role / Timing Role: Primary-side voltage sense element feeding optocoupler feedback network. Use Value: Enables stable 18 V output regulation with <1% drift across −40°C to +85°C ambient via low TCR Zener characteristics. |
| Low-voltage Adapter Protection | Industrial Sensor Signal Conditioning |
Use Scenario: Overvoltage clamp on 24 V adapter output rails protecting downstream logic. IC Role / Device Role / Timing Role: Transient voltage suppressor activated above 18.36 V to divert surge energy. Use Value: Limits clamping voltage to ≤18.4 V while sustaining 500 mW peak pulse power per JEDEC standards. | Use Scenario: Providing stable 18 V excitation for resistive bridge sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Precision voltage source for ratiometric measurement reference. Use Value: Delivers <50 ppm/°C effective tempco via matched Zener and resistor tempcos in bridge interface design. |
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 | Same 18 V nominal, ±5% tolerance (vs. ±2%), 350 mW rating, SOT-23 package | Higher thermal resistance limits continuous power in compact layouts; less precise for reference use | Select when cost priority outweighs voltage accuracy and board space allows SOT-23 footprint |
| 1N4746A | 18 V nominal, ±5%, 1 W rating, DO-41 through-hole package | Requires manual insertion or wave soldering; unsuitable for fully SMT production | Choose only for prototyping or legacy through-hole systems where 0805 placement is unavailable |
Compared with MMBZ5245B-7-F and 1N4746A, the BZY55B18 RBG delivers tighter voltage tolerance and SMT-compatible 0805 packaging essential for high-density, automated manufacturing of precision voltage references - without sacrificing thermal performance or reliability.
Availability
BZY55B18 RBG is available at Aetrix Electronics and suitable for LED lighting regulation, on-board DC/DC converter reference, and industrial sensor signal conditioning requiring stable component supply across high-volume production cycles.
Supply support for BZY55B18 RBG 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global industrial, computing, and consumer markets since 1979.
The BZY55B series belongs to TSC's precision Zener diode product line, engineered specifically for surface-mount voltage reference and stabilization in space-constrained, thermally demanding applications such as power supplies and sensor interfaces.
FAQ
What is the exact Zener voltage range for BZY55B18 RBG?
The BZY55B18 RBG has a guaranteed Zener voltage range of 17.64 V to 18.36 V at 5 mA test current (IZT), reflecting its ±2% tolerance around the nominal 18.0 V rating. This range is validated per Taiwan Semiconductor's D2301 specification document and applies under pulse-test conditions (10 ms duration). The BZY55B18 RBG maintains this tolerance across its qualified operating temperature range.
Is BZY55B18 RBG RoHS compliant and lead-free?
Yes, the BZY55B18 RBG is RoHS compliant and lead-free, as confirmed in the "Features" section of Taiwan Semiconductor's official datasheet (Version D2301). The device uses lead-free terminations and complies with EU Directive 2011/65/EU, with full material declarations available upon request from Aetrix Electronics for compliance documentation.
What is the maximum power dissipation of BZY55B18 RBG at room temperature?
The BZY55B18 RBG has a maximum power dissipation (PD) of 500 mW at TA = 25°C, as specified in the Absolute Maximum Ratings table. Derating is required above 25°C ambient, following the 300°C/W junction-to-ambient thermal resistance - e.g., maximum PD drops to ~330 mW at 75°C ambient. This rating applies to the 0805 ceramic package under still-air conditions.
Does BZY55B18 RBG have a defined cathode marking?
Yes, the BZY55B18 RBG features a visible cathode band on the top surface of the 0805 ceramic body, consistent with industry-standard polarity marking for surface-mount Zener diodes. This band aligns with the cathode terminal (Pad K) and must be oriented toward the higher-potential node when used in reverse-bias regulation mode.
What is the leakage current specification for BZY55B18 RBG?
The BZY55B18 RBG exhibits a maximum leakage current (IR) of 0.1 µA when biased at 13.0 V reverse voltage (VR), as specified in the Electrical Specifications table. This low leakage supports energy-efficient operation in always-on reference circuits and ensures minimal loading on high-impedance feedback nodes in precision power supply designs.
BZY55B18 RBG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- 0805 (2012 Metric)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 50 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 13 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 0805
BZY55B18 RBG FAQ
1.How can I place an order for BZY55B18 RBG through Aetrix?
Please submit a Request for Quotation (RFQ) for BZY55B18 RBG 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 BZY55B18 RBG reliable?
The price and inventory of BZY55B18 RBG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZY55B18 RBG is usually 5 days.
3.What payment methods are accepted for BZY55B18 RBG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZY55B18 RBG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZY55B18 RBG?
BZY55B18 RBG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZY55B18 RBG 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 BZY55B18 RBG?
For technical support, including BZY55B18 RBG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZY55B18 RBG requirements.
6.How does Aetrix verify that BZY55B18 RBG is sourced from the original manufacturer or authorized distributors?
All BZY55B18 RBG 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 BZY55B18 RBG meets industry standards.
7.What is the process for return or replacement of BZY55B18 RBG?
All BZY55B18 RBG units undergo pre-shipment inspection (PSI). If there is an issue with BZY55B18 RBG, 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 BZY55B18 RBG part is unused and in its original packaging.
Return procedure for BZY55B18 RBG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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