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onsemi BZX85C30
- Part No.:
- BZX85C30
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZX85C30.pdf
- Description:
- DIODE ZENER 30V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:5,980
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Product details
Overview
BZX85C30 from onsemi is a 30 V, ±5% tolerance, 1.0 W axial-leaded Zener diode in DO-41 glass package, designed for voltage regulation and reference applications in power supplies, overvoltage protection circuits, and precision biasing networks where stable breakdown voltage and low dynamic impedance are required.
For engineers reviewing the BZX85C30 datasheet, pinout, applications, or equivalent options, key selection criteria include its 30 V nominal Zener voltage at 30 mA test current, 8 Ω maximum Zener impedance at IZ = 30 mA, 0.25 μA maximum leakage current at VR = 21 V, and thermal derating of 6.67 mW/°C above 50°C ambient.
Technical Context
The BZX85C30 operates as a silicon planar Zener diode with controlled avalanche breakdown at 30 V, specified under thermal equilibrium conditions at lead temperature TL = 30°C ±1°C and 3/8″ lead length. Its DO-41 glass package provides hermetic sealing and reliable high-temperature operation up to +200°C junction temperature.
It delivers stable regulation across -65°C to +200°C storage and operating range, with 1.0 W power dissipation at TA = 25°C and 1.3 W at TL = 25°C (4 mm from package). The 5% voltage tolerance and low ZZK = 1000 Ω at IZK = 0.25 mA support precise clamping in low-current reference paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.0–32.0 V at IZ = 30 mA - defines regulated output voltage window for design margining |
| Zener Impedance (ZZ) | 8 Ω max @ IZ = 30 mA - ensures minimal output voltage variation under load changes |
| Leakage Current (IR) | 0.25 μA max @ VR = 21 V - guarantees negligible standby current in high-impedance bias networks |
| Power Dissipation (PD) | 1.0 W @ TA = 25°C - sets maximum continuous power handling without heatsinking |
| Thermal Derating | 6.67 mW/°C above 50°C - determines safe power reduction for elevated ambient temperatures |
| Junction Temp Range | -65°C to +200°C - enables use in automotive under-hood and industrial high-temp environments |
Pinout & Package
DO-41 glass axial package with cathode indicated by color band; two-terminal device with anode and cathode leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward bias | Connected to lower-potential node in reverse-biased Zener configuration |
| Cathode | Current exit terminal during reverse breakdown | Marked with color band; connected to higher-potential node for voltage clamping |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables predictable regulation without post-production trimming in cost-sensitive designs |
| Low Zener impedance (8 Ω) | Minimizes output voltage drift under varying load currents in feedback references |
| Hermetically sealed DO-41 glass package | Ensures long-term stability and moisture resistance in harsh industrial environments |
| High junction temperature rating (+200°C) | Supports operation in enclosed enclosures or near heat-generating components |
Applications
| Power Supply Regulation | Overvoltage Protection |
|---|---|
Use Scenario: Stabilizing reference voltage in linear regulator feedback loops and DC-DC converter error amplifiers. IC Role / Device Role / Timing Role: Voltage reference element providing fixed 30 V reference point for error sensing. Use Value: Maintains ±5% output accuracy across temperature and load, reducing need for external calibration. |
Use Scenario: Clamping transient surges on 24 V industrial control lines to prevent damage to downstream logic inputs. IC Role / Device Role / Timing Role: Shunt protection device conducting excess energy to ground when line voltage exceeds 32 V. Use Value: Limits peak voltage to ≤32 V with <0.25 μA leakage below 21 V, minimizing standby power loss. |
| Precision Biasing | Signal Level Translation |
Use Scenario: Generating stable bias points for op-amp input stages in sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Low-noise voltage reference source for setting common-mode or offset voltages. Use Value: Delivers 30 V reference with 8 Ω dynamic impedance, suppressing supply-induced ripple in analog front-ends. |
Use Scenario: Translating TTL-level signals to 30 V logic thresholds in PLC input modules. IC Role / Device Role / Timing Role: Threshold-setting clamp defining high-state detection level for industrial digital inputs. Use Value: Provides sharp, repeatable switching threshold with minimal hysteresis due to tight 5% VZ tolerance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5257B | 30 V, ±5%, 0.5 W, DO-35 package, higher ZZ = 35 Ω | Lower power rating limits use in >500 mW regulation; smaller DO-35 footprint | Select for space-constrained PCBs where 0.5 W suffices and thermal mass is limited |
| MMBZ5257ELT1G | 30 V, ±5%, 0.35 W, SOT-23 package, ZZ = 35 Ω, surface-mount | Not suitable for through-hole designs; requires reflow assembly and lacks DO-41 ruggedness | Choose for automated high-volume production needing compact, solder-reflow compatible packaging |
Compared with 1N5257B and MMBZ5257ELT1G, the BZX85C30 offers higher power handling (1.0 W vs. 0.5 W/0.35 W) and lower dynamic impedance (8 Ω vs. 35 Ω), making it preferable for robust, thermally demanding regulation tasks where axial mounting and glass-seal reliability are prioritized.
Availability
BZX85C30 is available at Aetrix Electronics and suitable for power supply regulation, overvoltage protection, and precision biasing applications requiring stable component supply, long-lifecycle availability, and consistent parametric performance across manufacturing lots.
Supply support for BZX85C30 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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BZX85C30 belongs to the BZX85C series of general-purpose Zener diodes engineered for reliable voltage reference and clamping in cost-sensitive, high-reliability industrial and power systems.
FAQ
What is the nominal Zener voltage and tolerance of the BZX85C30?
The BZX85C30 has a nominal Zener voltage of 30 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 28.0 V and 32.0 V when tested at IZ = 30 mA and TL = 30°C ±1°C. This specification is verified per onsemi's BZX85C3V3–BZX85C56 datasheet Rev. 2 (October 2017), and applies directly to the BZX85C30 device under standard thermal test conditions.
What is the maximum power dissipation for the BZX85C30 at room temperature?
The BZX85C30 is rated for 1.0 W maximum power dissipation at ambient temperature TA = 25°C. At lead temperature TL = 25°C (measured 4 mm from the glass package), it supports up to 1.3 W. Power must be derated linearly by 6.67 mW/°C above 50°C ambient, as defined in the Absolute Maximum Ratings table of the official onsemi datasheet for BZX85C30.
Does the BZX85C30 have a specified Zener impedance, and what does it mean for circuit design?
Yes, the BZX85C30 has a maximum Zener impedance (ZZ) of 8 Ω at IZ = 30 mA. This low dynamic impedance means the device maintains stable regulation - voltage change per unit current change is minimized - enabling tighter output voltage control in feedback loops and reference circuits. It directly impacts load regulation performance in BZX85C30-based designs.
What package type and marking identify the BZX85C30?
The BZX85C30 uses the DO-41 (JEDEC DO-204AL) axial glass package with cathode identified by a color band. Marking consists of five lines: ON Semiconductor logo (Line 1), "85C" (Line 2), "30" denoting voltage (Line 3), large die identification character (Line 4), and two-digit six-week date code (Line 5), per onsemi's top-marking specification for the BZX85C series.
What is the leakage current specification for the BZX85C30, and at what reverse voltage is it measured?
The BZX85C30 specifies a maximum leakage current (IR) of 0.25 μA at VR = 21 V, measured at TA = 25°C. This ultra-low leakage ensures minimal current draw in high-impedance bias networks and prevents unintended loading of sensitive analog nodes - a critical parameter confirmed in the Electrical Characteristics table of the BZX85C3V3–BZX85C56 datasheet for the BZX85C30 variant.
BZX85C30 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±7%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 21 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
BZX85C30 FAQ
1.How can I place an order for BZX85C30 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX85C30 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 BZX85C30 reliable?
The price and inventory of BZX85C30 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX85C30 is usually 5 days.
3.What payment methods are accepted for BZX85C30?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX85C30 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX85C30?
BZX85C30 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX85C30 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 BZX85C30?
For technical support, including BZX85C30 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX85C30 requirements.
6.How does Aetrix verify that BZX85C30 is sourced from the original manufacturer or authorized distributors?
All BZX85C30 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 BZX85C30 meets industry standards.
7.What is the process for return or replacement of BZX85C30?
All BZX85C30 units undergo pre-shipment inspection (PSI). If there is an issue with BZX85C30, 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 BZX85C30 part is unused and in its original packaging.
Return procedure for BZX85C30:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX85C30 Tags
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