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Microchip Technology 1N4737AUR/TR
- Part No.:
- 1N4737AUR/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4737AUR/TR.pdf
- Description:
- DIODE ZENER 7.5V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,502
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Product details
Overview
1N4737AUR/TR from Microsemi is a surface-mount 1.0 W glass-encapsulated Zener diode with a nominal Zener voltage of 7.5 V ±5%, 4.0 mA test current, 4.0 Ω dynamic impedance at IZT, 5 μA maximum reverse leakage at 6.0 V, and 121 mA maximum Zener current at TA = 50°C. It serves as a precision voltage reference or shunt regulator in power supply feedback loops, analog signal conditioning, and overvoltage protection circuits.
For engineers reviewing the 1N4737AUR/TR datasheet, 1N4737AUR/TR pinout, 1N4737AUR/TR application, or 1N4737AUR/TR equivalent, key selection criteria include its DO-213AB MELF glass package, hermetic sealing for high-reliability environments, -65°C to +175°C operating temperature range, and RoHS-compliant e3 termination option.
Technical Context
This device operates in reverse-bias breakdown mode to maintain stable voltage across its terminals under varying load and line conditions. Its Zener regulation is defined at 4.0 mA test current (IZT) with sharp knee characteristics verified by dual-point impedance measurement per Note 2.
The 1N4737AUR/TR exhibits 121 mA maximum steady-state Zener current at 50°C ambient when mounted on FR4 with recommended footprint, and thermal resistance of 130°C/W junction-to-ambient - critical for thermal design in compact, high-density PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.5 V ±5% - defines regulated output voltage tolerance in shunt regulation applications |
| Test Current (IZT) | 4.0 mA - required bias current to achieve specified VZ and dynamic impedance |
| Dynamic Impedance (ZZT) | 4.0 Ω @ IZT - low AC impedance ensures minimal voltage variation under dynamic load changes |
| Reverse Leakage (IR) | 5 μA @ 6.0 V - confirms low standby power loss below regulation threshold |
| Max Zener Current (IZM) | 121 mA @ TA = 50°C - sets upper continuous operating current limit with thermal derating |
| Power Dissipation | 1.0 W @ TEC < 125°C - rated power handling at end-cap temperature, not ambient |
| Operating Temperature | -65°C to +175°C - enables use in aerospace, downhole, and industrial extreme-environment systems |
Pinout & Package
Package: DO-213AB glass MELF (Metal Electrode Leadless Face) - hermetically sealed, leadless cylindrical surface-mount package with cathode band marking. Dimensions: A = 2.39–2.66 mm (length), B = 4.80–5.20 mm (diameter), C = 0.41–0.55 mm (band width).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Regulated output node | Connected to higher-potential side in shunt configuration; voltage referenced to anode |
| Anode (unbanded end) | Reference/ground node | Typically tied to system ground or lower-potential rail; completes Zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Enables operation in high-humidity, corrosive, or radiation-prone environments without degradation |
| JEDEC DO-213AB compliant outline | Ensures compatibility with standard SMT pick-and-place equipment and reflow profiles |
| Nonsensitive to ESD | Eliminates need for external ESD protection during handling and assembly |
| Inherently radiation hard | Validated per MicroNote 050 for total ionizing dose (TID) resilience in space-grade applications |
| RoHS-compliant e3 termination | Tin-plated terminals meet lead-free soldering requirements and MIL-STD-750 Method 2026 |
Applications
| Power Supply Feedback Regulation | Analog Signal Clamping |
|---|---|
Use Scenario: Stabilizing output voltage in isolated DC-DC converter feedback networks using optocoupler-coupled error amplifiers. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 7.5 V reference to TL431 or similar error amplifier inputs. Use Value: Maintains ±1% output regulation accuracy over temperature and line variations due to tight 7.5 V ±5% tolerance and low 4.0 Ω ZZT. | Use Scenario: Limiting input signal swing to protect ADC front-end stages from overvoltage transients. IC Role / Device Role / Timing Role: Bidirectional clamping diode (with series resistor) limiting analog input to ±7.5 V relative to reference rail. Use Value: Prevents ADC saturation and latch-up while preserving signal fidelity via fast response and low leakage (5 μA @ 6.0 V). |
| Overvoltage Protection Circuit | High-Reliability Reference Source |
Use Scenario: Safeguarding microcontroller I/O pins against ESD or surge events exceeding 7.5 V. IC Role / Device Role / Timing Role: Primary shunt clamp absorbing transient energy before it reaches sensitive logic inputs. Use Value: Withstands 121 mA continuous Zener current and 1.0 W dissipation, enabling robust protection without external active components. | Use Scenario: Providing stable voltage reference in avionics sensor signal conditioning modules requiring long-term stability. IC Role / Device Role / Timing Role: Precision Zener reference replacing bulkier IC references where size, weight, and radiation tolerance are critical. Use Value: Hermetic glass seal and -65°C to +175°C rating ensure drift-free operation in uncontrolled thermal environments over 20+ 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 |
|---|---|---|---|
| 1N4737A-T | Same 7.5 V ±5% Zener voltage, but in DO-41 axial package; higher thermal resistance (70°C/W junction-to-ambient) | Requires through-hole mounting and larger board area; unsuitable for ultra-high-density SMT designs | Select when legacy through-hole assembly or manual prototyping is preferred over automated SMT |
| SMAJ4737A | Same electrical specs but in SMA package; plastic body instead of glass; no inherent radiation hardness | Lacks hermeticity and radiation tolerance; limited to commercial/industrial temperature range (-65°C to +150°C) | Choose for cost-sensitive consumer applications where radiation immunity and extended temperature are not required |
Compared with 1N4737A-T and SMAJ4737A, the 1N4737AUR/TR uniquely combines surface-mount compatibility, hermetic glass reliability, full military-grade temperature range, and radiation hardness - making it the only option qualified for aerospace, downhole, and high-integrity industrial control systems.
Availability
1N4737AUR/TR is available at Aetrix Electronics and suitable for power supply feedback regulation, analog signal clamping, overvoltage protection, and high-reliability reference source applications requiring stable component supply across extended temperature and radiation-exposed environments.
Supply support for 1N4737AUR/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-performance analog and mixed-signal components.
The 1N4737AUR/TR belongs to Microsemi's surface-mount glass Zener diode family designed specifically for mission-critical voltage regulation where hermetic sealing, wide temperature operation, and radiation tolerance are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N4737AUR/TR?
The 1N4737AUR/TR has a nominal Zener voltage of 7.5 V with a tolerance of ±5%, indicated by the "A" suffix in its part number. This tolerance is guaranteed over the full operating temperature range of -65°C to +175°C and is verified per JEDEC test methods described in the official Microsemi datasheet revision D.
Does the 1N4737AUR/TR require heatsinking in typical applications?
The 1N4737AUR/TR does not require external heatsinking when operated within its 1.0 W power rating and mounted on FR4 with the recommended pad layout. Its thermal resistance is 130°C/W junction-to-ambient under those conditions, allowing safe operation up to 121 mA at 50°C ambient - sufficient for most shunt regulation tasks without added thermal mass.
Is the 1N4737AUR/TR compatible with lead-free reflow soldering processes?
Yes, the 1N4737AUR/TR features RoHS-compliant e3 termination with annealed matte-tin plating, qualified for lead-free reflow soldering at 260°C for up to 10 seconds. Its glass MELF body withstands repeated thermal cycling without cracking or delamination, meeting IPC-J-STD-020 moisture sensitivity level 1 requirements.
How is polarity identified on the 1N4737AUR/TR?
Polarity on the 1N4737AUR/TR is marked by a single cathode band near one end of the cylindrical glass body. The banded end is the cathode and must be connected to the higher-potential node in Zener regulation circuits; the unbanded end is the anode and connects to the lower-potential or ground reference point.
Can the 1N4737AUR/TR replace axial 1N4737A diodes in existing designs?
No direct drop-in replacement is possible due to differing packages: the 1N4737AUR/TR uses DO-213AB MELF surface-mount packaging, while the axial 1N4737A uses DO-41. Board redesign is required to accommodate the smaller footprint, different thermal profile, and SMT assembly process - though electrical behavior remains functionally identical.
1N4737AUR/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):
- 7.5 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 4 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 5 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)
1N4737AUR/TR FAQ
1.How can I place an order for 1N4737AUR/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4737AUR/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 1N4737AUR/TR reliable?
The price and inventory of 1N4737AUR/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4737AUR/TR is usually 5 days.
3.What payment methods are accepted for 1N4737AUR/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4737AUR/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4737AUR/TR?
1N4737AUR/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4737AUR/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 1N4737AUR/TR?
For technical support, including 1N4737AUR/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4737AUR/TR requirements.
6.How does Aetrix verify that 1N4737AUR/TR is sourced from the original manufacturer or authorized distributors?
All 1N4737AUR/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 1N4737AUR/TR meets industry standards.
7.What is the process for return or replacement of 1N4737AUR/TR?
All 1N4737AUR/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4737AUR/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 1N4737AUR/TR part is unused and in its original packaging.
Return procedure for 1N4737AUR/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4737AUR/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
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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