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onsemi 1N5257B
- Part No.:
- 1N5257B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5257B.pdf
- Description:
- DIODE ZENER 33V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:4,681
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Product details
Overview
1N5257B from ON Semiconductor is a 33 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation, 58 Ω dynamic impedance at 14 mA test current, and 0.25 μA reverse leakage at 25.2 V. It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.
For engineers reviewing the 1N5257B datasheet, pinout, applications, or equivalent options, this device serves as a standard through-hole Zener for fixed-voltage clamping, biasing, and voltage reference generation where ±5% tolerance and stable TC (0.092 %/°C) are required.
Technical Context
The 1N5257B operates as a two-terminal silicon Zener diode with avalanche breakdown mechanism, optimized for stable DC voltage regulation at nominal 33 V. Its 58 Ω Zener impedance (ZZ) at IZ = 14 mA ensures predictable voltage drop under moderate load variation, while its 0.092 %/°C temperature coefficient enables predictable drift compensation in ambient-temperature-stable designs.
Designed for operation within -65 °C to +200 °C junction temperature range and rated for 500 mW at 25 °C (derating 4.0 mW/°C above 50 °C), the device supports reliable performance in industrial and automotive auxiliary circuits where hermetic glass packaging and lead-free compatibility are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 33 V nominal, min 31.35 V / max 34.65 V at IZ = 14 mA - defines regulated output voltage window under specified test conditions |
| Power Dissipation (PD) | 500 mW at TA = 25 °C - maximum continuous power handling before thermal derating begins |
| Zener Impedance (ZZ) | 58 Ω at IZ = 14 mA - indicates voltage stability against current variation; lower values improve regulation accuracy |
| Reverse Leakage (IR) | 0.25 μA at VR = 25.2 V - confirms minimal off-state conduction below breakdown threshold |
| Temperature Coefficient (TC) | +0.092 %/°C - quantifies VZ drift per degree Celsius; positive sign indicates increasing VZ with temperature |
| Package | DO-35 glass case with cathode band - hermetically sealed, axial-leaded, JEDEC-standard footprint for manual or wave soldering |
Pinout & Package
DO-35 glass package: axial-leaded, hermetically sealed, cathode identified by color band. Dimensions per JEDEC DO-204AH: body length 4.56 mm, diameter 1.91 mm, lead length ≥25.4 mm, weight 0.137 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode-side reference node | Connected to lower-potential side in reverse-biased regulation; used for forward voltage drop (≤1.2 V @ 200 mA) if forward-biased |
| Cathode | Zener breakdown terminal / voltage reference output | Marked with color band; connected to higher-potential side in regulation mode; delivers stable 33 V when reverse-biased above knee voltage |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Ensures tight initial calibration without external trimming in cost-sensitive voltage reference designs |
| Hermetic DO-35 glass package | Provides long-term reliability and moisture resistance in harsh environments without conformal coating |
| Low reverse leakage (0.25 μA) | Minimizes quiescent current draw in battery-powered or high-impedance bias networks |
| Controlled temperature coefficient (+0.092 %/°C) | Enables predictable thermal drift modeling for applications requiring <±1% total VZ variation across -40 °C to +85 °C |
Applications
| Industrial Sensor Signal Conditioning | Automotive Body Control Module Reference |
|---|---|
Use Scenario: Stabilizing excitation voltage for resistive bridge sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Zener diode providing fixed 33 V reference for op-amp biasing and ADC reference scaling. Use Value: Maintains <±0.5% reference stability over 0–70 °C due to low TC and tight tolerance, reducing sensor gain error. | Use Scenario: Clamping microcontroller I/O voltage during load-dump transients in door module ECUs. IC Role / Device Role / Timing Role: Overvoltage protection element shunting surge energy above 33 V to ground. Use Value: Withstands 500 mW peak pulse energy and responds in <10 ns, preventing latch-up in 3.3 V logic interfaces. |
| Consumer Audio Power Supply Regulation | Medical Diagnostic Equipment Bias Network |
Use Scenario: Generating clean ±15 V rails from unregulated transformer outputs in headphone amplifier PSUs. IC Role / Device Role / Timing Role: Low-noise Zener reference for discrete transistor-based linear regulators. Use Value: 58 Ω ZZ limits output ripple to <5 mVpp under 5 mA load variation, preserving audio SNR. | Use Scenario: Setting precise bias points for photodiode transimpedance amplifiers in portable blood oximeters. IC Role / Device Role / Timing Role: Stable voltage reference for feedback network calibration in ultra-low-current analog front-ends. Use Value: 0.25 μA leakage avoids introducing >10 pA error current, critical for sub-nA signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4749A | 33 V nominal, ±5%, 1 W rating, DO-41 package, 30 Ω ZZ at 38 mA | Higher power handling but larger footprint; requires different PCB layout and thermal relief | Select when >500 mW continuous dissipation or lower impedance is required; not drop-in compatible |
| BZX55C33 | 33 V nominal, ±5%, 500 mW, DO-35, 70 Ω ZZ at 5 mA, -0.05 %/°C TC | Negative TC improves compensation in some temp-critical references; slightly higher impedance at lower test current | Prefer when negative TC aligns with system drift budget; same package but verify IZ operating point match |
Compared with 1N4749A and BZX55C33, the 1N5257B offers optimal balance of DO-35 footprint compatibility, 58 Ω impedance at industry-standard 14 mA test current, and predictable +0.092 %/°C drift-making it ideal for space-constrained, thermally stable 33 V reference designs where 500 mW suffices.
Availability
1N5257B is available at Aetrix Electronics and suitable for industrial sensor conditioning, automotive ECU protection, and consumer audio power supply regulation requiring stable component supply and full traceability.
Supply support for 1N5257B 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, high-performance silicon solutions for automotive, industrial, cloud computing, and IoT applications.
The 1N52xxB series is part of ON Semiconductor's legacy Zener diode portfolio designed specifically for general-purpose voltage regulation, reference, and protection in cost-sensitive, high-reliability through-hole applications.
FAQ
What is the nominal Zener voltage and tolerance of the 1N5257B?
The 1N5257B has a nominal Zener voltage of 33 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 31.35 V and 34.65 V when tested at 14 mA. This specification is verified per ON Semiconductor's 1N5221B–1N5263B datasheet Rev. 3, and applies directly to the 1N5257B device under standard thermal equilibrium conditions.
What is the Zener impedance (ZZ) of the 1N5257B and why does it matter?
The 1N5257B exhibits a Zener impedance of 58 Ω at IZ = 14 mA. This value quantifies how much the output voltage changes per unit change in current-lower ZZ means tighter regulation. For the 1N5257B, 58 Ω ensures voltage deviation remains under ±0.1 V for ±2 mA load shifts, supporting stable biasing in analog circuits.
Can the 1N5257B be used in surface-mount designs?
No-the 1N5257B is exclusively packaged in the axial-leaded DO-35 glass case and is not available in SMD variants. It requires through-hole mounting and wave or hand soldering. For SMT equivalents, consider ON Semiconductor's NZ9F33V or similar SOD-123 Zeners-but those are not pin-compatible replacements for the 1N5257B.
What is the maximum reverse leakage current for the 1N5257B and at what voltage is it specified?
The 1N5257B specifies a maximum reverse leakage current of 0.25 μA at VR = 25.2 V (90% of nominal VZ). This low leakage ensures minimal parasitic current draw in high-impedance reference networks and preserves accuracy in battery-powered systems where standby current must remain sub-microamp.
How does the temperature coefficient of the 1N5257B affect its performance across operating temperature?
The 1N5257B has a temperature coefficient of +0.092 %/°C, meaning its Zener voltage increases by approximately 30.4 mV per °C rise. Over a -40 °C to +85 °C range, this results in ~3.8 V total drift-so system-level compensation or operating within narrower ambient bands is recommended when absolute voltage stability is critical for the 1N5257B.
1N5257B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 58 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 25 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-35
1N5257B FAQ
1.How can I place an order for 1N5257B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5257B 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 1N5257B reliable?
The price and inventory of 1N5257B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5257B is usually 5 days.
3.What payment methods are accepted for 1N5257B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5257B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5257B?
1N5257B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5257B 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 1N5257B?
For technical support, including 1N5257B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5257B requirements.
6.How does Aetrix verify that 1N5257B is sourced from the original manufacturer or authorized distributors?
All 1N5257B 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 1N5257B meets industry standards.
7.What is the process for return or replacement of 1N5257B?
All 1N5257B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5257B, 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 1N5257B part is unused and in its original packaging.
Return procedure for 1N5257B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5257B Tags
-
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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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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