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onsemi 1N5946B
- Part No.:
- 1N5946B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N5946B.pdf
- Description:
- DIODE ZENER 75V 3W AXIAL
- Quantity:
- Payment:
- Shipping:
Inventory:4,198
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Product details
Overview
1N5946B from onsemi is a 3 W, 75 V ±5% Zener diode in DO-41 axial package, designed for precision voltage regulation and overvoltage protection in DC power supplies, reference circuits, and surge-clamping applications. It delivers 56 mA maximum DC zener current, 5.0 Ω typical zener impedance at 140 mA test current, and operates across −65°C to +200°C junction temperature range.
For engineers reviewing the 1N5946B datasheet, pinout, applications, or equivalent options, key selection criteria include its 75 V nominal zener voltage with tight ±5% tolerance, 98 W non-repetitive surge rating at 1 ms, ESD robustness (>16 kV HBM), and thermal performance under lead-temperature-limited dissipation conditions.
Technical Context
The 1N5946B implements a silicon-oxide passivated PN junction optimized for stable reverse-biased breakdown regulation. Its zener voltage is specified at TL = 30°C with 3/8″ lead length, and it exhibits a positive temperature coefficient above ~5 V - consistent with its 75 V nominal rating and measured TC near +0.085%/°C per onsemi Figure 6.
Thermal design relies on junction-to-lead conduction (primary path via cathode lead), with transient thermal resistance θJL(t) defined for pulse widths ≥0.1 s and derating curves referenced to lead temperature (TL), not ambient. Steady-state power dissipation is rated at 3 W @ TL = 75°C, derating linearly to zero at 125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 71.25–78.75 V @ IZT = 140 mA; ensures ±5% regulation accuracy under stable DC bias conditions. |
| Max DC Zener Current (IZM) | 56 A max; defines absolute upper limit of continuous reverse current before thermal runaway risk. |
| Zener Impedance (ZZT) | 5.0 Ω @ IZT = 140 mA; determines AC regulation error and output voltage ripple suppression capability. |
| Surge Power Rating | 98 W @ 1 ms non-repetitive; supports transient overvoltage clamping without failure in power supply input stages. |
| ESD Rating | Class 3 (>16 kV) per HBM; enables robust handling and board-level reliability in unshielded industrial environments. |
| Operating Temperature | −65°C to +200°C junction range; permits use in automotive engine compartments and industrial motor controls. |
| Package | DO-41 (Case 59), axial-lead, Pb-free; compatible with standard through-hole wave-soldering and manual assembly processes. |
Pinout & Package
DO-41 plastic axial package (Case 59, Style 1) with cathode indicated by a single band. Leads are corrosion-resistant, solderable, and rated for 260°C @ 1/16″ from case for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Reverse-bias anode connection point | Connected to higher-potential node in regulation/clamp configuration; carries full zener current during operation. |
| Anode (unbanded end) | Reverse-bias cathode reference | Typically tied to system ground or low-side return; establishes reference potential for regulated output voltage. |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Guaranteed 71.25–78.75 V range eliminates need for post-production trimming in fixed-voltage references. |
| 3 W steady-state power rating | Enables compact, cost-effective regulation without heatsinking in low-power auxiliary rails (e.g., 12 V → 5 V bias supplies). |
| 98 W 1 ms surge capability | Clamps lightning-induced transients or inductive kickback in relay drivers and solenoid interfaces without degradation. |
| ESD >16 kV (HBM) | Reduces field-failure risk during handling, PCB assembly, and operation in electrostatic-prone factory environments. |
| Pb-free DO-41 package | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow compliance for global manufacturing deployment. |
Applications
| Voltage Reference for Analog Sensors | Overvoltage Clamp in DC Power Inputs |
|---|---|
|
Use Scenario: Providing stable 75 V reference for high-voltage current sensing amplifiers in battery management systems. IC Role / Device Role / Timing Role: Precision shunt reference establishing known voltage threshold for comparator-triggered fault detection. Use Value: Maintains <±0.5% drift over −40°C to +105°C ambient due to low TC and tight initial tolerance, enabling accurate cell overvoltage cutoff. |
Use Scenario: Protecting downstream DC-DC converters from 100 V surges on 48 V telecom power distribution lines. IC Role / Device Role / Timing Role: Fast-acting shunt clamp diverting transient energy away from sensitive switching controllers. Use Value: Absorbs 98 W for 1 ms without parametric shift or bond-wire fusing, preserving system uptime during lightning events. |
| Field-Programmable Gate Array (FPGA) Configuration Supply Clamp | Industrial PLC Input Protection |
|
Use Scenario: Limiting programming voltage to 75 V on FPGA configuration pins during hot-swap insertion into backplane slots. IC Role / Device Role / Timing Role: Standby-mode voltage limiter preventing gate oxide damage during unexpected voltage excursions. Use Value: Activates within nanoseconds at 78.75 V (max VZ), limiting stress to <10 ns beyond threshold - faster than most TVS diodes in same package. |
Use Scenario: Shielding 24 V digital input channels in programmable logic controllers from 200 V EFT bursts per IEC 61000-4-4. IC Role / Device Role / Timing Role: Primary front-end surge suppressor in optocoupler-isolated input stage. Use Value: Withstands repeated 100× 200 V/100 ns pulses at 5 kHz due to low thermal mass and robust oxide passivation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5365B | 75 V ±5%, 5 W rating in DO-201AD package; higher power but larger footprint and different thermal path. | Preferred where >3 W continuous dissipation is required or where surface-mount layout constraints prohibit axial leads. | Select 1N5365B only if system-level thermal analysis confirms junction temperature remains ≤175°C at 5 W. |
| BZX85C75 | 75 V ±5%, 1.3 W rating in DO-41; identical package but lower power and higher ZZT (20 Ω vs. 5.0 Ω). | Suitable for low-current bias networks (<10 mA) but inadequate for active clamping or high-precision references. | Choose BZX85C75 only when cost sensitivity outweighs regulation stability and surge immunity requirements. |
Compared with 1N5946B, 1N5365B offers higher power headroom at the expense of PCB area and lead-length-dependent thermal management, while BZX85C75 sacrifices regulation fidelity and transient robustness for lower unit cost in non-critical signal conditioning.
Availability
1N5946B is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and telecom infrastructure equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for 1N5946B 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, medical, and IoT applications.
The 1N59xxB series was engineered for high-reliability voltage regulation in harsh-environment power systems, emphasizing tight tolerance, surge resilience, and extended temperature operation - distinguishing it from general-purpose Zener families.
FAQ
What is the guaranteed zener voltage range for 1N5946B?
The 1N5946B guarantees a reverse zener voltage range of 71.25 V to 78.75 V at IZT = 140 mA and lead temperature TL = 30°C. This ±5% tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet (Rev. 9, July 2024), and applies to all units marked "1N5946B, G".
Can 1N5946B be used in surface-mount designs?
No - the 1N5946B is exclusively packaged in the axial-lead DO-41 (Case 59) format and is not available in SMD variants. It requires through-hole mounting with minimum 3/8″ lead length for full 3 W power rating. For SMT alternatives, consider the 1N5365B in DO-201AD or BZX85C75 in DO-41-compatible SOD-123 packages - neither is pin-compatible with 1N5946B.
What is the maximum allowable surge current for 1N5946B?
The 1N5946B supports up to 98 W of non-repetitive surge power for 1 ms, corresponding to a peak surge current of approximately 1.31 A (calculated as √(98 W / 75 V)). This value is derived from Figure 3 in the onsemi datasheet and assumes TJ = 25°C prior to pulse. Repetitive surges require derating per duty cycle and thermal time constants shown in Figure 2.
How does temperature affect the zener voltage of 1N5946B?
The 1N5946B exhibits a positive temperature coefficient of approximately +0.085%/°C near its 75 V nominal rating, as indicated in onsemi's Figure 6 (Units 10 to 400 Volts). This means VZ increases by ~64 mV/°C over its operating range. For precision applications, junction temperature must be controlled or compensated using the thermal model in the Application Note (page 5).
Is 1N5946B RoHS compliant and lead-free?
Yes - the "G" suffix in 1N5946B, G explicitly denotes a Pb-free package per onsemi's ordering information (page 1). The device meets RoHS Directive 2011/65/EU and uses lead-free terminations compatible with standard SnAgCu reflow profiles. Full compliance documentation is available in onsemi's Pb-Free Packaging Strategy reference (SOLDERRM/D).
1N5946B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 75 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 140 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 56 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- Axial
1N5946B FAQ
1.How can I place an order for 1N5946B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5946B 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 1N5946B reliable?
The price and inventory of 1N5946B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5946B is usually 5 days.
3.What payment methods are accepted for 1N5946B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5946B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5946B?
1N5946B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5946B 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 1N5946B?
For technical support, including 1N5946B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5946B requirements.
6.How does Aetrix verify that 1N5946B is sourced from the original manufacturer or authorized distributors?
All 1N5946B 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 1N5946B meets industry standards.
7.What is the process for return or replacement of 1N5946B?
All 1N5946B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5946B, 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 1N5946B part is unused and in its original packaging.
Return procedure for 1N5946B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5946B 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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