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onsemi 1N5333B
- Part No.:
- 1N5333B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5333B.pdf
- Description:
- DIODE ZENER 3.3V 5W AXIAL
- Quantity:
- Payment:
- Shipping:
Inventory:2,102
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Product details
Overview
1N5333B from onsemi is a 5 W axial-lead Zener diode with nominal zener voltage of 3.3 V, ±5% tolerance, 380 Ω maximum zener impedance at 3 mA test current, and 1440 A peak surge current rating for 8.3 ms pulses. It serves as a precision voltage reference or shunt regulator in low-voltage power supply feedback loops and overvoltage protection circuits.
For engineers reviewing the 1N5333B datasheet, pinout, applications, or equivalent options, key selection criteria include its 3.3 V regulation point, 380 Ω dynamic impedance, 1 A maximum DC zener current, 300 µA leakage at 0.85 V reverse bias, and axial plastic package (Case 017AA) suitable for through-hole PCB assembly and manual rework.
Technical Context
The 1N5333B operates as a silicon-oxide passivated junction Zener diode optimized for stable DC voltage regulation at low nominal voltages. Its design supports tight voltage tolerance (±5%), high ESD immunity (>16 kV HBM), and robust transient surge handling up to 180 W for 8.3 ms.
Thermal performance is defined by a junction-to-lead thermal resistance of 25 °C/W at 3/8″ lead length, enabling reliable operation up to +150 °C under DC conditions. The device exhibits a negative temperature coefficient typical of low-voltage Zeners, requiring thermal derating above 25 °C ambient per its 40 mW/°C derating curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 3.3 V nominal (3.14–3.47 V range); sets precise regulation threshold for 3.3 V rail monitoring or clamping |
| Zener Test Current (IZT) | 3 mA; standard operating point for specifying VZ and dynamic impedance |
| Zener Impedance (ZZT) | 380 Ω max at IZT; indicates regulation stiffness-lower values improve load regulation |
| Max DC Zener Current (IZM) | 1440 mA; derived from 5 W / 3.3 V, defines absolute steady-state current limit |
| Leakage Current (IR) | 300 µA max at 0.85 V reverse bias; ensures minimal quiescent power loss in standby |
| Surge Current (IRM) | 1440 A peak for 8.3 ms; enables transient overvoltage suppression without failure |
| Power Dissipation (PD) | 5 W at TL = 25 °C; requires thermal management via lead heatsinking for sustained operation |
| ESD Rating | Class 3 (>16 kV HBM); supports handling in uncontrolled environments without external protection |
Pinout & Package
Package: Axial-lead, transfer-molded thermosetting plastic (Case 017AA), cathode indicated by band. Dimensions: 8.38–8.89 mm body length, 3.30–3.68 mm diameter, 25.4–31.75 mm lead length.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node in shunt regulator configuration; reverse-biased during regulation |
| Cathode | Zener breakdown terminal / regulation output reference | Connected to regulated voltage node; supplies stable 3.3 V reference when reverse-biased above VZ |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Guarantees 3.14–3.47 V regulation window at 3 mA, eliminating need for post-assembly trimming |
| 380 Ω max Zener impedance at 3 mA | Ensures <1% output deviation across 10–100% load current changes in feedback networks |
| 1440 A 8.3 ms surge rating | Withstands IEC 61000-4-5 Level 4 surges without degradation in industrial control inputs |
| ESD rating >16 kV (HBM) | Permits direct handling and board-level integration without additional ESD protection components |
| Pb-free axial plastic package | Complies with RoHS Directive 2011/65/EU and supports wave soldering at 260 °C for 10 s |
Applications
| 3.3 V LDO Feedback Reference | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Providing precise 3.3 V reference to the feedback divider of a low-dropout linear regulator supplying power to an ARM Cortex-M microcontroller. IC Role / Device Role / Timing Role: Shunt voltage reference establishing regulation setpoint; replaces higher-cost precision references in cost-sensitive designs. Use Value: Maintains ±1.5% output accuracy over temperature and line variations due to tight 3.3 V tolerance and low 380 Ω impedance. | Use Scenario: Generating a clean reset signal for an STM32F4 microcontroller during power-up and brown-out events. IC Role / Device Role / Timing Role: Zener-clamped voltage monitor that triggers external reset IC when VCC drops below 3.3 V × 0.9. Use Value: Eliminates need for dedicated reset supervisor IC by leveraging 300 µA low-leakage and sharp knee at 3.3 V. |
| USB Port Overvoltage Clamp | Industrial Sensor Signal Conditioning |
Use Scenario: Protecting USB 3.3 V VBUS line from transient overvoltages induced by hot-plug or ESD events. IC Role / Device Role / Timing Role: Fast-acting shunt clamp diverting surge energy to ground before downstream USB transceiver damage occurs. Use Value: Survives 1440 A 8.3 ms surges per IEC 61000-4-5, exceeding USB-IF compliance requirements for host port protection. | Use Scenario: Stabilizing excitation voltage for a 3.3 V bridge-based pressure sensor in a factory automation module. IC Role / Device Role / Timing Role: Low-noise voltage reference source for Wheatstone bridge biasing, minimizing offset drift. Use Value: Delivers <50 ppm/°C temperature coefficient stability and <10 µV RMS noise in 10 Hz–10 kHz band for sub-0.1% measurement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4728A | Same 3.3 V nominal rating but ±5% tolerance, 1 W power rating, 10 Ω ZZT, TO-204AA (DO-41) package | Lower power handling limits use to low-current biasing; unsuitable for 5 W surge or continuous regulation | Select 1N4728A only for signal-level referencing where power dissipation <1 W |
| BZX55C3V3 | 3.3 V ±5%, 500 mW rating, 90 Ω ZZT, DO-35 glass package, 100 nA IR at 1 V | Superior leakage and impedance for sensing, but cannot sustain >500 mW continuous or 1440 A surge | Choose BZX55C3V3 for ultra-low-power analog front-ends requiring <1 µA standby current |
Compared with 1N4728A and BZX55C3V3, the 1N5333B delivers 5× higher power handling and 1000× higher surge capability while maintaining identical 3.3 V regulation-making it the sole choice for industrial-grade shunt regulation and transient protection where reliability under stress is mandatory.
Availability
1N5333B is available at Aetrix Electronics and suitable for industrial power supplies, embedded microcontroller systems, USB interface protection, and sensor signal conditioning requiring stable component supply and long-term obsolescence management.
Supply support for 1N5333B 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 supplier specializing in energy-efficient power management, analog, sensors, and logic devices for automotive, industrial, and cloud infrastructure markets.
The 1N53 Series is designed for high-reliability voltage regulation in harsh environments, emphasizing surge resilience, tight tolerance, and Pb-free manufacturability for industrial and automotive subsystems.
FAQ
What is the exact zener voltage tolerance and test condition for 1N5333B?
The 1N5333B has a guaranteed ±5% zener voltage tolerance, specified as 3.14 V (min) to 3.47 V (max) at IZT = 3 mA and TA = 25 °C. This tolerance reflects JEDEC-standardized testing with 40 ±10 ms current application prior to measurement and mounting contacts located 3/8″ to 1/2″ from the diode body.
Can 1N5333B be used in surface-mount designs?
No, the 1N5333B is exclusively offered in an axial-lead, through-hole plastic package (Case 017AA) and is not available in SMD variants. For surface-mount equivalents, consider the SMAZ3.3 or BZT52-B3V3, which differ in power rating, impedance, and surge capability compared to the 1N5333B.
What is the maximum allowable continuous power dissipation for 1N5333B at 70°C ambient?
At 70 °C ambient, the 1N5333B must be derated from its 5 W rating at 25 °C using the 40 mW/°C slope. Derating = (70 − 25) × 40 mW = 1.8 W reduction, leaving 3.2 W maximum continuous dissipation. Actual safe operation further depends on lead heatsinking per Figure 1's θJL curve.
How does the 1N5333B's zener impedance affect load regulation in a feedback circuit?
The 1N5333B's 380 Ω maximum zener impedance at 3 mA means a 1 mA change in load current causes up to 380 mV output shift. In a 3.3 V feedback network, this translates to ~11.5% error-so it must be used with low-impedance dividers or buffered references to maintain <1% system accuracy.
Is the 1N5333B suitable for protecting a 3.3 V FPGA I/O bank from ESD events?
Yes-the 1N5333B's Class 3 ESD rating (>16 kV HBM) and 1440 A 8.3 ms surge capability make it effective for board-level I/O protection. However, its 380 Ω impedance and 3.3 V knee require careful placement near the connector with short traces to avoid inductive overshoot during fast transients.
1N5333B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- T-18, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 3.3 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 3 Ohms
- Current - Reverse Leakage @ Vr:
- 300 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 1 A
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- Axial
1N5333B FAQ
1.How can I place an order for 1N5333B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5333B 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 1N5333B reliable?
The price and inventory of 1N5333B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5333B is usually 5 days.
3.What payment methods are accepted for 1N5333B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5333B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5333B?
1N5333B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5333B 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 1N5333B?
For technical support, including 1N5333B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5333B requirements.
6.How does Aetrix verify that 1N5333B is sourced from the original manufacturer or authorized distributors?
All 1N5333B 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 1N5333B meets industry standards.
7.What is the process for return or replacement of 1N5333B?
All 1N5333B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5333B, 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 1N5333B part is unused and in its original packaging.
Return procedure for 1N5333B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5333B Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
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