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Microchip Technology 1N4740UR/TR
- Part No.:
- 1N4740UR/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4740UR/TR.pdf
- Description:
- DIODE ZENER 10V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,758
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Product details
Overview
1N4740UR/TR from Microsemi is a surface-mount 1.0 W glass-encapsulated Zener diode with a nominal Zener voltage of 10 V ±5%, 25 mA test current, 7 Ω dynamic impedance at IZT, and maximum reverse current of 10 µA at 7.6 V. It operates from −65 °C to +175 °C and is used for precision voltage regulation in high-density power supply feedback loops and reference circuits.
For engineers reviewing the 1N4740UR/TR datasheet, 1N4740UR/TR pinout, 1N4740UR/TR application, or 1N4740UR/TR equivalent, key selection criteria include its DO-213AB MELF glass package, hermetic sealing, radiation-hardened performance per MicroNote 050, and tight thermal resistance (50 °C/W junction-to-end-cap) for stable regulation under thermal stress.
Technical Context
This device functions as a two-terminal voltage reference diode operating in reverse breakdown. Its Zener voltage is specified at 30 °C with 90-second stabilization time post-current application, and it maintains regulation across a broad current range (0.25 mA to 91 mA) with low dynamic impedance and sharp knee characteristics verified by dual-point Zener impedance measurement.
The 1N4740UR/TR uses a hermetically sealed DO-213AB glass MELF case with cathode band polarity marking and tin-lead or RoHS-compliant matte-tin plating. It delivers stable regulation without ESD sensitivity and supports high-reliability applications where source control drawings (SCD) mandate hermeticity and radiation tolerance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 10 V ±5% - defines precise regulation threshold for feedback networks |
| Test Current (IZT) | 25 mA - standardized bias point for VZ measurement and impedance characterization |
| Dynamic Impedance (ZZT) | 7 Ω @ IZT - ensures minimal output voltage variation under load transients |
| Max Reverse Current (IR) | 10 µA @ 7.6 V - guarantees low leakage in standby and low-power modes |
| Power Dissipation | 1.0 W @ TEC < 125 °C - enables compact thermal design with end-cap heatsinking |
| Operating Temperature | −65 °C to +175 °C - supports aerospace, downhole, and industrial environments |
| Thermal Resistance | 50 °C/W junction-to-end-cap - allows direct thermal path to PCB copper or metal mounting |
Pinout & Package
Package: DO-213AB glass MELF - hermetically sealed, leadless cylindrical surface-mount package with cathode band marking; polarity requires banded end to be positive during Zener operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reverse-biased terminal during regulation | Connected to lower-potential node; forms reference return path in shunt regulator |
| Cathode | Zener breakdown terminal | Banded end; connected to regulated voltage node; carries full load current in shunt configuration |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Enables operation in high-humidity, corrosive, or vacuum environments without parameter drift |
| Radiation hardness (per MicroNote 050) | Supports space-grade and nuclear instrumentation applications without derating |
| Nonsensitive to ESD | Eliminates need for on-board ESD protection circuitry in handling and assembly |
| Stable capacitance (specified in Figure 2) | Predictable high-frequency behavior for noise-sensitive analog references and timing circuits |
| RoHS-compliant option (e3 suffix) | Meets environmental compliance requirements without sacrificing electrical or thermal performance |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Used in optocoupler-coupled feedback loop of isolated DC-DC converters to regulate output voltage. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 10 V reference to TL431 or optocoupler LED anode. Use Value: Low dynamic impedance (7 Ω) minimizes output ripple; hermetic seal prevents long-term drift in harsh factory environments. | Use Scenario: Provides excitation voltage for precision RTD or strain gauge bridges in process control transmitters. IC Role / Device Role / Timing Role: Two-terminal voltage reference establishing fixed bias point for bridge completion and ADC reference scaling. Use Value: −65 °C to +175 °C operating range ensures calibration stability across ambient extremes; radiation hardness supports nuclear plant instrumentation. |
| Aerospace Power Conditioning | High-Reliability Test Equipment |
Use Scenario: Embedded in avionics DC bus monitors for overvoltage clamp and reference generation. IC Role / Device Role / Timing Role: Zener clamp protecting downstream monitoring ICs; also serves as primary reference for ADC front-end. Use Value: Radiation hardness per MicroNote 050 eliminates single-event latch-up risk; DO-213AB package withstands mechanical shock and thermal cycling. | Use Scenario: Calibrated voltage standard in automated test equipment (ATE) power supply modules. IC Role / Device Role / Timing Role: Precision shunt reference used in closed-loop calibration of programmable voltage sources. Use Value: ±5% tolerance and sharp knee impedance ensure repeatable, traceable reference accuracy; hermetic seal preserves calibration integrity over 10+ year service life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4740AUR | Same Zener voltage (10 V), same DO-213AB package, but no tape-and-reel (TR) packaging; lacks TR suffix | Not optimized for automated SMT placement; requires manual or bulk loading | Select 1N4740UR/TR when volume production with pick-and-place is required |
| SMAJ4740A | Same 10 V rating but in SMA package; higher thermal resistance (junction-to-ambient ~130 °C/W); plastic body, not hermetic | Limited to commercial-grade reliability; unsuitable for radiation-hardened or high-humidity applications | Choose SMAJ4740A only for cost-sensitive, non-critical consumer designs where hermeticity is unnecessary |
Compared with 1N4740AUR and SMAJ4740A, the 1N4740UR/TR uniquely combines tape-and-reel automation readiness, hermetic glass MELF construction, and radiation hardness-making it the sole choice for high-reliability, high-volume SMT deployments requiring long-term parametric stability.
Availability
1N4740UR/TR is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor interfaces, aerospace power monitors, and high-reliability test equipment requiring stable component supply across extended temperature and radiation environments.
Supply support for 1N4740UR/TR 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, radiation-hardened, and high-voltage analog components.
The 1N4740UR/TR belongs to Microsemi's surface-mount Zener diode family designed for voltage regulation in mission-critical systems where hermeticity, wide temperature range, and radiation tolerance are mandatory-not just desirable.
FAQ
What is the Zener voltage tolerance of the 1N4740UR/TR?
The 1N4740UR/TR has a nominal Zener voltage of 10 V with a tolerance of ±5%, as indicated by the "A" suffix in its designation. This tolerance is guaranteed across the full operating temperature range of −65 °C to +175 °C and is measured after 90 seconds of dc current application per datasheet Note 4. The 1N4740UR/TR does not support tighter tolerances (e.g., ±1% or ±2%)-those require suffixes "D" or "C", respectively.
Does the 1N4740UR/TR have a defined forward voltage specification?
Yes-the 1N4740UR/TR specifies a maximum forward voltage of 1.2 V at 200 mA forward current. This parameter is relevant for reverse-polarity protection checks and transient clamping analysis. Unlike its Zener regulation characteristics, the forward conduction behavior is not optimized for rectification; the device is intended exclusively for reverse-bias Zener operation.
Is the 1N4740UR/TR suitable for automated SMT assembly?
Yes-the "TR" suffix explicitly denotes tape-and-reel packaging per EIA-481-B standard (12 mm tape, 1500 units per 7-inch reel). The DO-213AB MELF package is compatible with standard SMT pick-and-place equipment when using appropriate nozzle and vision calibration. No special tooling is required beyond standard MELF-handling settings.
How does the 1N4740UR/TR achieve radiation hardness?
The 1N4740UR/TR achieves inherent radiation hardness through its hermetically sealed glass MELF (DO-213AB) construction and proprietary silicon processing detailed in Microsemi MicroNote 050. This design prevents total ionizing dose (TID) degradation and mitigates single-event effects-enabling use in space, nuclear, and high-altitude applications without external shielding or derating.
Can the 1N4740UR/TR replace axial-leaded 1N4740A in existing designs?
No direct drop-in replacement is possible-the 1N4740UR/TR uses a DO-213AB MELF surface-mount package, while the 1N4740A uses a DO-41 axial-leaded package. PCB layout, thermal pad design, and reflow profile must be revised. However, their electrical parameters (10 V ±5%, 1 W, 7 Ω ZZT) are identical, enabling functional equivalence after board redesign.
1N4740UR/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AB, MELF (Glass)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 10 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 7 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 7.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AB (MELF, LL41)
1N4740UR/TR FAQ
1.How can I place an order for 1N4740UR/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4740UR/TR 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 1N4740UR/TR reliable?
The price and inventory of 1N4740UR/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4740UR/TR is usually 5 days.
3.What payment methods are accepted for 1N4740UR/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4740UR/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4740UR/TR?
1N4740UR/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4740UR/TR 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 1N4740UR/TR?
For technical support, including 1N4740UR/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4740UR/TR requirements.
6.How does Aetrix verify that 1N4740UR/TR is sourced from the original manufacturer or authorized distributors?
All 1N4740UR/TR 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 1N4740UR/TR meets industry standards.
7.What is the process for return or replacement of 1N4740UR/TR?
All 1N4740UR/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4740UR/TR, 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 1N4740UR/TR part is unused and in its original packaging.
Return procedure for 1N4740UR/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4740UR/TR 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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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
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SMAZ12-13-F
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