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onsemi BZX79C30_T50R
- Part No.:
- BZX79C30_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
BZX79C30_T50R.pdf
- Description:
- DIODE ZENER 30V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:3,042
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Product details
Overview
BZX79C30_T50R from ON Semiconductor is a 30 V, ±5% tolerance Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C, with 80 Ω dynamic impedance at 2 mA test current and 0.05 μA maximum leakage current at 23.1 V reverse voltage. It provides precise voltage regulation in low-power reference and protection circuits.
For engineers reviewing the BZX79C30_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior (4.0 mW/°C above 75°C), junction temperature range (–65 to +200°C), and DO-35 mechanical compatibility in space-constrained analog designs.
Technical Context
This device operates as a two-terminal voltage reference, clamping reverse-biased voltage at its nominal 30 V zener point with specified dynamic impedance and temperature coefficient. Its electrical behavior is defined under thermal equilibrium at lead temperature TL = 30°C ± 1°C with 3/8″ lead length.
The BZX79C30_T50R exhibits a negative temperature coefficient of –2.0 mV/°C and capacitance of 25 pF at VZ = 0 V, f = 1 MHz. It is not intended for surge suppression or high-current transient clamping due to its 500 mW continuous rating and 2 mA nominal test current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.0 V min / 32.0 V max at IZ = 2 mA - defines usable regulation band for precision biasing |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - sets maximum steady-state thermal load in leaded PCB layout |
| Dynamic Impedance (ZZ) | 80 Ω max @ IZ = 2 mA - determines output voltage stability under small-signal load variation |
| Leakage Current (IR) | 0.05 μA max @ VR = 23.1 V - ensures minimal error current in high-impedance reference nodes |
| Temp. Coefficient (TC) | –2.0 mV/°C - quantifies voltage drift per degree Celsius in temperature-sensitive circuits |
| Junction Temp. Range | –65°C to +200°C - supports operation in automotive under-hood and industrial ambient extremes |
| Capacitance (C) | 25 pF @ VZ = 0 V, f = 1 MHz - impacts high-frequency noise filtering and AC coupling performance |
Pinout & Package
DO-35 glass axial package with cathode indicated by color band; two-terminal device with no internal polarity reversal or auxiliary pins.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node | Connected to circuit common when used in reverse-bias regulation configuration |
| Cathode | Zener breakdown terminal / Regulated output node | Provides stable 30 V reference potential relative to anode under reverse bias |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables predictable regulation without post-manufacture trimming in cost-sensitive consumer electronics |
| DO-35 glass package | Provides hermetic sealing and thermal stability for long-term reliability in humid or corrosive environments |
| –65°C to +200°C operating range | Supports deployment in engine control units, power supply feedback loops, and industrial sensor interfaces |
| Low leakage (0.05 μA) | Minimizes quiescent current draw in battery-powered voltage monitor circuits |
| Negative TC (–2.0 mV/°C) | Compensates for positive TC components (e.g., silicon references) in composite temperature-stable references |
Applications
| Overvoltage Protection | Voltage Reference |
|---|---|
Use Scenario: Clamping transient spikes on 24 V DC power rails in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Standalone shunt regulator absorbing excess energy during ESD or inductive kick events. Use Value: Limits rail voltage to ≤32 V using only passive components, avoiding need for active TVS or crowbar circuits. | Use Scenario: Providing stable bias voltage for op-amp input stages in precision analog signal conditioning. IC Role / Device Role / Timing Role: Low-drift, low-noise DC reference source for amplifier offset nulling networks. Use Value: Delivers <32 V regulation with <80 Ω impedance, enabling sub-mV output error in 12-bit data acquisition systems. |
| Power Supply Feedback | Sensor Excitation |
Use Scenario: Setting regulated output voltage in isolated flyback converter feedback path via optocoupler divider. IC Role / Device Role / Timing Role: Primary-side voltage sense element determining closed-loop regulation setpoint. Use Value: Maintains ±5% output accuracy across line/load/temperature with minimal external parts count. | Use Scenario: Supplying excitation voltage to resistive temperature detectors (RTDs) in HVAC control panels. IC Role / Device Role / Timing Role: Stable, low-noise excitation source minimizing self-heating and measurement drift. Use Value: Enables <0.1% full-scale error in 3-wire RTD bridges due to tight 30 V ±5% tolerance and low leakage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4745A | Same 30 V nominal, but ±5% tolerance, 1 W rating, DO-41 package | Higher power handling enables use in higher-current regulation; larger footprint requires PCB redesign | Select when >500 mW dissipation is required and board space allows DO-41 |
| BZX55C30 | 30 V, ±5%, 500 mW, DO-35, but 100 Ω ZZ max @ 20 mA (vs. 80 Ω @ 2 mA) | Higher test current shifts regulation point; less stable at low bias currents typical in reference designs | Prefer BZX79C30_T50R where low-current stability (<5 mA) is critical |
Compared with 1N4745A and BZX55C30, the BZX79C30_T50R offers tighter low-current impedance (80 Ω @ 2 mA) and DO-35 form factor ideal for compact analog boards, while trading off power headroom and high-current regulation fidelity.
Availability
BZX79C30_T50R is available at Aetrix Electronics and suitable for overvoltage protection, voltage reference, power supply feedback, and sensor excitation requiring stable component supply across automotive, industrial, and instrumentation programs.
Supply support for BZX79C30_T50R 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
ON Semiconductor is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The BZX79C series was designed for general-purpose voltage regulation and reference in cost-sensitive, space-constrained analog circuits requiring stable, low-leakage Zener performance in standard DO-35 packaging.
FAQ
What is the nominal Zener voltage and tolerance of the BZX79C30_T50R?
The BZX79C30_T50R 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 2 mA reverse current and thermal equilibrium conditions. This tolerance band is confirmed in the ON Semiconductor datasheet revision 3 and applies directly to the BZX79C30_T50R device marking "30" on the third line of its DO-35 package.
What is the maximum power dissipation and thermal derating for BZX79C30_T50R?
The BZX79C30_T50R is rated for 500 mW power dissipation at lead temperature (TL) ≤ 75°C, with a linear derating of 4.0 mW/°C above that temperature. This means at TL = 100°C, its usable power drops to 400 mW. The specification assumes 3/8″ lead length and is validated under thermal equilibrium at 30°C ± 1°C lead temperature, as defined in the official ON Semiconductor datasheet.
What is the dynamic impedance (ZZ) of BZX79C30_T50R and why does it matter?
The BZX79C30_T50R has a maximum dynamic impedance of 80 Ω measured at IZ = 2 mA. This value reflects how tightly the diode maintains its Zener voltage under small changes in current - lower ZZ means better regulation stability in precision reference applications. Unlike higher-current Zeners (e.g., 1N47xx series), this low-test-current specification makes BZX79C30_T50R especially suitable for micro-power bias networks.
Does BZX79C30_T50R have a specified temperature coefficient, and what is its value?
Yes, the BZX79C30_T50R has a temperature coefficient of –2.0 mV/°C, indicating its Zener voltage decreases by approximately 2 mV per degree Celsius rise in junction temperature. This negative TC is typical for Zeners in the 27–39 V range and is useful for compensating positive TC elements in composite reference designs, such as bandgap-based IC references.
What package type and marking identify the BZX79C30_T50R?
The BZX79C30_T50R uses the DO-35 glass axial package with cathode identified by a color band. Its top marking consists of three lines: first line is the ON Semiconductor logo (F), second line reads "9C", and third line displays "30" - confirming its 30 V rating per ON Semiconductor's marking standard for BZXxx series devices. This matches the official top-mark information table in the BZX79C2V4–BZX79C56 datasheet.
BZX79C30_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 21 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 100 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
BZX79C30_T50R FAQ
1.How can I place an order for BZX79C30_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX79C30_T50R 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 BZX79C30_T50R reliable?
The price and inventory of BZX79C30_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX79C30_T50R is usually 5 days.
3.What payment methods are accepted for BZX79C30_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX79C30_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX79C30_T50R?
BZX79C30_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX79C30_T50R 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 BZX79C30_T50R?
For technical support, including BZX79C30_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX79C30_T50R requirements.
6.How does Aetrix verify that BZX79C30_T50R is sourced from the original manufacturer or authorized distributors?
All BZX79C30_T50R 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 BZX79C30_T50R meets industry standards.
7.What is the process for return or replacement of BZX79C30_T50R?
All BZX79C30_T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX79C30_T50R, 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 BZX79C30_T50R part is unused and in its original packaging.
Return procedure for BZX79C30_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX79C30_T50R Tags
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