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Microchip Technology 1N5256B
- Part No.:
- 1N5256B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5256B.pdf
- Description:
- DIODE ZENER 30V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:7,341
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Product details
Overview
1N5256B from Microsemi is a 500 mW, 30 V ±5% glass axial-lead Zener diode in DO-35 (DO-204AH) package, designed for precision voltage regulation in low-power analog circuits, reference supplies, and overvoltage protection. It delivers stable 30 V regulation at 49 mA test current, with 600 Ω dynamic impedance and -65°C to +175°C operating temperature range.
For engineers reviewing the 1N5256B datasheet, 1N5256B pinout, 1N5256B application, or 1N5256B equivalent, key selection factors include its ±5% tolerance (B suffix), 0.1 μA max reverse leakage at 22 V, 0.5 W power rating with 250 °C/W thermal resistance, and cathode-band polarity marking for unambiguous orientation in PCB layout.
Technical Context
The 1N5256B operates as a two-terminal voltage reference device relying on controlled reverse-biased Zener breakdown. Its regulation stability is maintained across 1 mA to 100 mA operating current and full military temperature range (-65°C to +175°C), with minimal capacitance (<2 pF typical) enabling use in high-frequency bias networks.
It features a hermetically sealed glass DO-35 package with tin-lead or RoHS-compliant matte-tin plating, rated for 260°C soldering (10 s), and exhibits inherent radiation hardness per MicroNote 050 - making it suitable for aerospace and industrial environments where reliability under stress is critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 30 V ±5% at 49 mA test current - defines precise regulation point for reference and clamp circuits |
| Power Dissipation | 500 mW at 25°C, derated linearly to zero at 175°C - sets maximum continuous power handling on standard FR4 board |
| Zener Impedance | 600 Ω at IZK = 0.25 mA - indicates voltage stability under light-load or transient conditions |
| Reverse Leakage Current | 0.1 μA max at VR = 22 V - ensures minimal quiescent current draw in standby or high-impedance bias networks |
| Temperature Coefficient | +0.091 %/°C - quantifies voltage drift with ambient temperature change; enables compensation in precision references |
| Forward Voltage | 1.5 V max at 200 mA - defines conduction threshold in forward-bias protection or clamping configurations |
| Operating Temperature | -65°C to +175°C - supports deployment in extreme environments including automotive under-hood and downhole electronics |
Pinout & Package
DO-35 (DO-204AH) glass axial-leaded package: hermetically sealed, 0.2 g weight, cathode indicated by single black band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; forward conduction path when biased positive relative to cathode |
| Cathode | Banded end | Connected to higher-potential node during Zener operation; defines regulation reference point in shunt configuration |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N52xxB series | Industry-standard part numbering and electrical behavior - ensures interoperability and design continuity across suppliers |
| ±5% Zener voltage tolerance (B suffix) | Tighter regulation accuracy than A-suffix (±10%) parts - reduces need for post-regulation trimming in mid-precision applications |
| Minimal capacitance (<2 pF typical) | Preserves signal integrity in RF bias networks and high-speed clamp circuits without introducing parasitic loading |
| Radiation-hardened construction | Inherent hardness per MicroNote 050 - eliminates need for external shielding or qualification testing in space-qualified designs |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Robust handling during assembly - no special ESD controls required during manual or automated placement |
Applications
| Industrial Power Supply Reference | Automotive Sensor Bias Network |
|---|---|
Use Scenario: Providing stable 30 V reference for op-amp feedback in isolated DC-DC converter feedback loops. IC Role / Device Role / Timing Role: Shunt voltage reference regulating error amplifier input voltage. Use Value: Maintains ±0.5% output regulation over temperature and line variations due to tight 30 V ±5% tolerance and low tempco. |
Use Scenario: Biasing Hall-effect position sensors in engine control modules exposed to under-hood temperatures up to 150°C. IC Role / Device Role / Timing Role: Zener clamp protecting sensor IC supply rail from load-dump transients. Use Value: Survives -40°C to +150°C operation and 260°C reflow without parameter shift, ensuring long-term calibration stability. |
| Test Equipment Voltage Clamp | Aerospace Signal Conditioning |
Use Scenario: Limiting input voltage to ADC front-end in portable multimeters to prevent overrange damage. IC Role / Device Role / Timing Role: Precision shunt clamp limiting analog input to 30 V ±0.1 V. Use Value: Low 600 Ω Zener impedance ensures fast response to 100 ns transients while maintaining sub-1% clamping error. |
Use Scenario: Generating stable bias for radiation-tolerant amplifiers in satellite telemetry subsystems. IC Role / Device Role / Timing Role: Radiation-hardened voltage reference in analog signal chain. Use Value: Inherent radiation hardness eliminates need for redundant shielding or derating, reducing SWaP-C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5256C | ±2% tolerance (vs. ±5% for 1N5256B); same 30 V nominal, DO-35 package, and 500 mW rating | Higher precision required in metrology-grade references where <±0.6 V drift is unacceptable | Select 1N5256C only if tighter initial tolerance justifies cost premium and thermal drift remains within system budget |
| MMBZ5256B (SOT-23) | Same 30 V ±5%, but surface-mount MMBZ5256B in SOT-23 package; 350 mW power rating; different thermal profile | Used in space-constrained consumer electronics where axial leads are incompatible with automated assembly | Choose MMBZ5256B for high-volume PCB assembly; retain 1N5256B for through-hole prototyping, high-temp, or radiation-critical use |
Compared with 1N5256C and MMBZ5256B, the 1N5256B offers optimal balance of legacy compatibility, thermal robustness, and cost for industrial and aerospace applications requiring proven axial-leaded reliability - not merely form-fit replacement.
Availability
1N5256B is available at Aetrix Electronics and suitable for industrial power supply reference, automotive sensor bias network, and test equipment voltage clamp applications requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for 1N5256B 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N52xxB series was developed to deliver JEDEC-standardized, high-stability Zener regulation in hermetic glass packages for mission-critical voltage reference and protection functions across extreme environmental conditions.
FAQ
What is the Zener voltage tolerance of the 1N5256B?
The 1N5256B has a nominal Zener voltage of 30 V with a guaranteed tolerance of ±5%, as indicated by the "B" suffix per JEDEC specification. This tolerance is verified at 49 mA test current and 25°C ambient, and applies across the full operating temperature range (-65°C to +175°C) with defined temperature coefficient (+0.091 %/°C).
Can the 1N5256B be used in surface-mount designs?
No - the 1N5256B is packaged exclusively in the axial-leaded DO-35 (DO-204AH) glass case and is not compatible with surface-mount assembly. For SMT equivalents, consider the MMBZ5256B in SOT-23, which shares the same 30 V ±5% rating but has a reduced 350 mW power rating and different thermal characteristics.
What is the maximum reverse leakage current for the 1N5256B?
The 1N5256B specifies a maximum reverse leakage current (IR) of 0.1 μA at VR = 22 V (80% of nominal Zener voltage). This ultra-low leakage supports high-impedance bias networks and battery-powered applications where standby current must remain below 100 nA.
Is the 1N5256B suitable for high-temperature environments?
Yes - the 1N5256B is rated for continuous operation from -65°C to +175°C, with power derating beginning above 25°C. Its hermetic glass package and internal construction enable reliable performance in under-hood automotive, downhole oil/gas, and avionics applications where plastic-packaged alternatives would fail.
Does the 1N5256B require heatsinking in standard PCB layouts?
No - the 1N5256B dissipates up to 500 mW at 25°C with no external heatsink when mounted using standard 3/8″ (10 mm) lead length from the body. On FR4 boards with 4 mm² copper pads and 1 mm trace width, its thermal resistance is 310°C/W, allowing safe operation up to ~125°C ambient before derating becomes necessary.
1N5256B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 23 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N5256B FAQ
1.How can I place an order for 1N5256B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5256B 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 1N5256B reliable?
The price and inventory of 1N5256B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5256B is usually 5 days.
3.What payment methods are accepted for 1N5256B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5256B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5256B?
1N5256B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5256B 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 1N5256B?
For technical support, including 1N5256B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5256B requirements.
6.How does Aetrix verify that 1N5256B is sourced from the original manufacturer or authorized distributors?
All 1N5256B 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 1N5256B meets industry standards.
7.What is the process for return or replacement of 1N5256B?
All 1N5256B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5256B, 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 1N5256B part is unused and in its original packaging.
Return procedure for 1N5256B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5256B 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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