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onsemi BZX85C33_T50R
- Part No.:
- BZX85C33_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZX85C33_T50R.pdf
- Description:
- DIODE ZENER 33V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:4,783
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Product details
Overview
BZX85C33_T50R from onsemi is a 33 V, ±5% tolerance, 1.0 W axial-leaded Zener diode in DO-41 glass package, rated for 35 mA zener test current (IZ), with 1000 Ω maximum zener impedance (ZZ) at IZ and 0.25 μA maximum leakage current (IR) at 23 V reverse voltage - used for precision voltage regulation in power supply feedback loops and overvoltage protection circuits.
For engineers reviewing the BZX85C33_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating above 50°C (6.67 mW/°C), junction temperature range (–65°C to +200°C), and DO-41 mechanical compatibility with through-hole PCB layouts.
Technical Context
The BZX85C33_T50R operates as a silicon planar Zener diode with sharp reverse breakdown at 33 V nominal, designed for stable DC voltage reference under regulated current conditions. Its 1.0 W power dissipation at 25°C and 1.3 W at lead temperature (TL = 25°C, 4 mm from package) support moderate-power clamping and regulation tasks.
It exhibits 1000 Ω dynamic impedance at 35 mA test current and maintains ≤0.25 μA leakage at VR = 23 V, ensuring low standby loss in high-impedance bias networks. The DO-41 glass package provides hermetic sealing and meets JEDEC DO-204AL mechanical standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 31 V to 35 V at IZ = 35 mA - defines regulated output voltage window for feedback or clamp design |
| Tolerance | ±5% - determines worst-case voltage deviation in closed-loop regulation |
| Power Dissipation (PD) | 1.0 W at TA = 25°C - sets maximum continuous power handling without heatsinking |
| Zener Impedance (ZZ) | 1000 Ω max at IZ = 35 mA - impacts regulation stability under load transients |
| Leakage Current (IR) | 0.25 μA max at VR = 23 V - ensures minimal error current in high-Z reference paths |
| Junction Temp Range | –65°C to +200°C - supports operation in automotive under-hood and industrial environments |
| Forward Voltage (VF) | 1.2 V max at IF = 200 mA - relevant for polarity-check or ESD-diode reuse in bidirectional protection |
Pinout & Package
DO-41 glass axial package with cathode indicated by color band; two-terminal device requiring no orientation-specific PCB footprint beyond standard DO-41 hole spacing (lead diameter 0.51 mm, body diameter 2.72 mm, length 5.20 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reverse-biased reference return | Connected to lower-potential node in shunt regulator or clamp configuration |
| Cathode | Zener breakdown terminal / Reference output node | Connected to regulated voltage node; marked by color band per JEDEC DO-41 standard |
Key Features
| Feature | Design Value |
|---|---|
| Stable Zener voltage | 33 V nominal with ±5% tolerance ensures predictable regulation across production lots |
| Hermetic glass package | DO-41 glass construction provides moisture resistance and long-term parameter stability |
| High-temperature operation | Rated up to +200°C junction temperature enables use in engine control units and industrial motor drives |
| Low leakage performance | 0.25 μA max IR at 23 V minimizes loading error in precision voltage divider networks |
| Standardized mechanical form | JEDEC DO-204AL compliant footprint allows drop-in replacement with legacy BZX85 series parts |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Clamp for Microcontroller I/O |
|---|---|
Use Scenario: Regulating output voltage in flyback converter feedback path via optocoupler-coupled TL431 alternative. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 33 V threshold for error amplifier comparison. Use Value: Enables ±5% output accuracy without external trimming; 1000 Ω ZZ ensures minimal loop gain variation across line/load changes. |
Use Scenario: Protecting 3.3 V or 5 V GPIO pins against transient surges exceeding rail voltage. IC Role / Device Role / Timing Role: Passive clamping element diverting excess energy to ground when input exceeds 33 V. Use Value: 1.0 W power rating absorbs short-duration transients (e.g., IEC 61000-4-4) without degradation; DO-41 axial leads simplify board-level placement near connectors. |
| Industrial Sensor Signal Conditioning | Programmable Logic Controller (PLC) Input Protection |
Use Scenario: Biasing and limiting analog sensor outputs (e.g., 4–20 mA transmitter) before ADC input. IC Role / Device Role / Timing Role: Precision voltage limiter establishing upper signal bound at 33 V to prevent ADC saturation. Use Value: Low 0.25 μA leakage avoids offset errors in high-impedance sensor interfaces; ±5% VZ tolerance aligns with industrial 0.5% system accuracy targets. |
Use Scenario: Safeguarding 24 V DC digital inputs in factory automation systems exposed to inductive kickback. IC Role / Device Role / Timing Role: Standby shunt regulator clamping field-side transients before opto-isolator input stage. Use Value: –65°C to +200°C operating range matches PLC ambient requirements; DO-41 mounting allows direct soldering to DIN-rail mount PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5257B | 33 V, ±5%, 0.5 W, DO-35 package, 700 Ω ZZ @ 35 mA | Lower power rating limits use in >0.5 W clamping; smaller DO-35 footprint reduces thermal mass | Select when board space is constrained and peak power < 0.5 W; verify thermal relief on pads |
| MMSZ5257ET1G | 33 V, ±5%, 0.5 W, SOD-123 surface-mount package, 900 Ω ZZ @ 20 mA | SMD format eliminates through-hole assembly; lower test current shifts impedance curve | Choose for automated PCB assembly where DO-41 is incompatible; re-evaluate thermal design due to reduced copper area |
Compared with BZX85C33_T50R, the 1N5257B offers identical voltage specs but half the power rating and smaller package, while MMSZ5257ET1G provides SMT compatibility at the cost of derated power and different test-current impedance behavior - both require layout and thermal reassessment.
Availability
BZX85C33_T50R is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor interfaces, and programmable logic controller input protection requiring stable component supply and long-lifecycle availability.
Supply support for BZX85C33_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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BZX85C33_T50R belongs to the BZX85C family of general-purpose Zener diodes engineered for reliable voltage regulation and transient suppression in cost-sensitive, high-volume industrial and power applications.
FAQ
What is the zener voltage tolerance for BZX85C33_T50R?
The BZX85C33_T50R has a nominal zener voltage of 33 V with a guaranteed tolerance of ±5%, meaning its actual breakdown voltage falls between 31 V and 35 V when measured at 35 mA test current and 25°C ambient. This tolerance is specified in the official onsemi datasheet revision 2 (October 2017) and applies to all units shipped under this part number.
Can BZX85C33_T50R be used in surface-mount designs?
No, the BZX85C33_T50R uses a DO-41 axial glass package designed exclusively for through-hole mounting. For surface-mount alternatives, consider the MMSZ5257ET1G (SOD-123) or NZ9F33ST5G (SOD-923), both offering 33 V Zener voltage but requiring PCB redesign and thermal validation due to differing package thermal resistance and test conditions.
What is the maximum leakage current specification for BZX85C33_T50R?
The BZX85C33_T50R specifies a maximum leakage current (IR) of 0.25 μA at VR = 23 V and TA = 25°C. This value is critical for high-impedance bias networks and precision reference dividers, where even nanoamp-level leakage could introduce measurable error - confirmed in Table 1 of the onsemi BZX85C3V3–BZX85C56 datasheet.
How does thermal derating work for BZX85C33_T50R above 50°C?
The BZX85C33_T50R must be derated linearly at 6.67 mW/°C above 50°C ambient temperature. For example, at 75°C ambient, allowable power drops to 1.0 W − (25 × 0.00667 W) = 0.833 W. This derating ensures junction temperature remains within the –65°C to +200°C safe operating range and is defined in the Absolute Maximum Ratings table of the official datasheet.
Is BZX85C33_T50R suitable for automotive under-hood applications?
Yes, the BZX85C33_T50R supports junction temperatures up to +200°C and operates from –65°C, meeting extended temperature requirements for non-safety-critical automotive under-hood functions such as sensor biasing and power rail monitoring. However, it is not AEC-Q200 qualified; for certified automotive use, consult onsemi's AEC-Q200-compliant Zener portfolio like the 1SMA5929BT3G.
BZX85C33_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 33 V
- Tolerance:
- ±6%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 35 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 23 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
BZX85C33_T50R FAQ
1.How can I place an order for BZX85C33_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX85C33_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 BZX85C33_T50R reliable?
The price and inventory of BZX85C33_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX85C33_T50R is usually 5 days.
3.What payment methods are accepted for BZX85C33_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX85C33_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX85C33_T50R?
BZX85C33_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX85C33_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 BZX85C33_T50R?
For technical support, including BZX85C33_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX85C33_T50R requirements.
6.How does Aetrix verify that BZX85C33_T50R is sourced from the original manufacturer or authorized distributors?
All BZX85C33_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 BZX85C33_T50R meets industry standards.
7.What is the process for return or replacement of BZX85C33_T50R?
All BZX85C33_T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX85C33_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 BZX85C33_T50R part is unused and in its original packaging.
Return procedure for BZX85C33_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX85C33_T50R Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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Diodes Incorporated
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MMSZ4682T1G
onsemi
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Diodes Incorporated
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MM5Z5V1ST1G
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Micro Commercial Co
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Diodes Incorporated
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