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Microchip Technology 1N4737UR-1/TR
- Part No.:
- 1N4737UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AB, MELF (Glass)
- Datasheet:
-
1N4737UR-1/TR.pdf
- Description:
- DIODE ZENER 7.5V 1W DO213AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,964
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Product details
Overview
1N4737UR-1/TR from Microsemi is a surface-mount 1.0 W glass Zener diode with a nominal Zener voltage of 7.5 V ±5%, DO-213AB (MELF) hermetic package, 34 mA test current, and 4.0 Ω dynamic impedance at IZT. It operates from –65 °C to +175 °C and delivers stable voltage regulation in high-density power supply feedback paths.
For engineers reviewing the 1N4737UR-1/TR datasheet, 1N4737UR-1/TR pinout, 1N4737UR-1/TR application, or 1N4737UR-1/TR equivalent, key selection criteria include Zener tolerance, thermal resistance (130 °C/W on FR4), surge current rating (700 mA), and RoHS-compliant matte-tin termination for reflow compatibility.
Technical Context
This device functions as a precision shunt voltage regulator, maintaining a stable 7.5 V reference across its cathode–anode terminals when reverse-biased above breakdown. Its glass MELF construction ensures low parasitic capacitance and inherent radiation hardness per MicroNote 050.
It exhibits a sharp Zener knee with 0.5 mA test current (IZK) and 45 Ω maximum knee impedance (ZZK), enabling reliable low-current regulation. The 1.2 V forward voltage at 200 mA supports polarity verification during functional testing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.5 V ±5% at 34 mA - defines regulated output voltage in feedback loops with predictable tolerance band |
| Power Dissipation | 1.0 W at TEC < 125 °C - sets maximum continuous power handling on end-cap heatsinking |
| Dynamic Impedance (ZZT) | 4.0 Ω at IZT = 34 mA - determines output voltage variation under load transients |
| Max Reverse Current (IR) | 5 μA at VR = 6.0 V - ensures minimal leakage below regulation threshold |
| Surge Current (IS) | 700 mA (½-sine, 1/120 s) - withstands short-duration overvoltage events without degradation |
| Operating Temperature | –65 °C to +175 °C - supports aerospace, downhole, and industrial environments without derating |
| Thermal Resistance | 130 °C/W junction-to-ambient on FR4 (1 oz Cu) - informs PCB pad design for thermal management |
Pinout & Package
DO-213AB (Glass MELF) hermetically sealed surface-mount package with axial symmetry; cathode identified by single black band. No discrete pins - terminals are metallized end caps soldered directly to PCB pads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Regulated output node | Connected to reference point (e.g., op-amp inverting input); must be held positive relative to anode for Zener operation |
| Anode (unbanded end) | Return/reference ground | Typically tied to system ground or feedback divider low-side; establishes current path through series resistor |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Eliminates moisture ingress and long-term parameter drift; enables >20-year reliability in sealed enclosures |
| Nonsensitive to ESD | No special handling required - withstands human-body-model discharges without parameter shift or failure |
| Specified capacitance (Figure 2) | Low junction capacitance (~10–20 pF typical) preserves high-frequency stability in switching regulator feedback networks |
| Inherent radiation hardness | Meets MIL-PRF-19500 requirements for total ionizing dose (TID) without additional screening |
| RoHS-compliant termination | Matte-tin plating meets JEDEC J-STD-020 reflow profile (260 °C/10 s) and eliminates lead-based solder concerns |
Applications
| Switching Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or forward converters via optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Shunt reference providing precise 7.5 V threshold to TL431-like control IC or comparator input. Use Value: Tight ±5% tolerance and low ZZT minimize output voltage drift across line/load/temperature variations. |
Use Scenario: Providing stable excitation voltage for resistive bridge sensors (e.g., strain gauges, RTDs) in process control systems. IC Role / Device Role / Timing Role: Low-drift voltage reference source for analog front-end instrumentation amplifiers. Use Value: Hermetic glass package prevents humidity-induced offset drift; wide temperature range ensures calibration stability from –40 °C to +85 °C ambient. |
| Aerospace Power Conditioning | Downhole Oilfield Electronics |
Use Scenario: Overvoltage clamping and rail stabilization in avionics DC-DC modules exposed to lightning-induced transients. IC Role / Device Role / Timing Role: Transient voltage suppressor and precision bias source in redundant power management units. Use Value: 700 mA surge rating and radiation-hardened structure meet DO-160 Section 22 Level 3 requirements without external TVS stacking. |
Use Scenario: Voltage regulation in high-temperature logging tools operating at 175 °C downhole. IC Role / Device Role / Timing Role: Primary shunt reference in high-temp ASIC bias networks and ADC reference buffers. Use Value: Full –65 °C to +175 °C operational range with no derating; glass seal prevents hydrogen embrittlement in H2S-rich environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4737AUR-1/TR | Same Zener voltage (7.5 V), identical DO-213AB package, but rated for ±5% tolerance with "A" suffix; same electrical specs and thermal performance | No functional difference - both qualified for high-reliability surface-mount use; "AUR" denotes Microsemi's standard A-grade screening | Select 1N4737AUR-1/TR if sourcing from legacy BOMs referencing "AUR" nomenclature; otherwise 1N4737UR-1/TR is functionally identical |
| BZX84-C7V5 | 7.5 V ±5%, SOT-23 plastic package, 300 mW power rating, higher ZZT (15 Ω), lower surge rating (500 mA), and narrower temp range (–65 °C to +150 °C) | Suitable for consumer-grade low-power regulators where size and cost outweigh reliability and thermal margin | Choose BZX84-C7V5 only for cost-sensitive, non-mission-critical designs; avoid where >1 W dissipation, >150 °C operation, or radiation hardness is required |
Compared with 1N4737AUR-1/TR and BZX84-C7V5, the 1N4737UR-1/TR offers identical regulation performance to the former while differing only in part-numbering convention, and provides superior power handling, thermal range, and ruggedness versus the latter's plastic SOT-23 alternative.
Availability
1N4737UR-1/TR is available at Aetrix Electronics and suitable for switching power supplies, industrial sensor interfaces, aerospace power conditioning, and downhole electronics requiring stable component supply across extended temperature and reliability lifecycles.
Supply support for 1N4737UR-1/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) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets, emphasizing radiation tolerance and extended temperature operation.
The 1N4737UR-1/TR belongs to Microsemi's surface-mount glass Zener diode family engineered for high-density, low-parasitic voltage regulation in mission-critical power and sensing systems where hermeticity and thermal robustness are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N4737UR-1/TR?
The 1N4737UR-1/TR has a nominal Zener voltage of 7.5 V with a tolerance of ±5%, as confirmed in the Electrical Characteristics table on page 2 of the Microsemi datasheet. This tolerance applies at 34 mA test current and 30 °C case temperature, and is maintained across its full operating temperature range of –65 °C to +175 °C.
Is the 1N4737UR-1/TR RoHS compliant?
Yes, the 1N4737UR-1/TR is RoHS compliant, indicated by the "e3" suffix in its full manufacturer designation (1N4737UR-1/TR,e3). It features annealed matte-tin plating per MIL-STD-750 Method 2026 and is qualified for lead-free reflow soldering at 260 °C for 10 seconds.
What package type does the 1N4737UR-1/TR use?
The 1N4737UR-1/TR uses the DO-213AB glass MELF (Metal Electrode Leadless Face) package - a hermetically sealed cylindrical surface-mount outline with metallized end-cap terminals. Its dimensions are 2.39–2.66 mm diameter and 4.80–5.20 mm length, per page 3 of the Microsemi datasheet.
Can the 1N4737UR-1/TR replace through-hole 1N4737A diodes?
The 1N4737UR-1/TR is electrically equivalent to the through-hole 1N4737A but is not a mechanical drop-in replacement. It uses DO-213AB surface-mount packaging versus DO-41 axial leads, requiring PCB redesign. Functionally, it delivers identical 7.5 V ±5% regulation and 1.0 W power dissipation in high-density layouts.
What is the maximum steady-state power dissipation for the 1N4737UR-1/TR on FR4?
The 1N4737UR-1/TR dissipates 1.0 W continuously when mounted on FR4 with 1 oz copper using the recommended footprint, up to an ambient temperature of 45 °C. Above that, power must be linearly derated at 130 °C/W - e.g., 0.5 W at 80 °C ambient - as shown in Figure 1 of the datasheet.
1N4737UR-1/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:
- ±10%
- 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)
1N4737UR-1/TR FAQ
1.How can I place an order for 1N4737UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4737UR-1/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 1N4737UR-1/TR reliable?
The price and inventory of 1N4737UR-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4737UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N4737UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4737UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4737UR-1/TR?
1N4737UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4737UR-1/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 1N4737UR-1/TR?
For technical support, including 1N4737UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4737UR-1/TR requirements.
6.How does Aetrix verify that 1N4737UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N4737UR-1/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 1N4737UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N4737UR-1/TR?
All 1N4737UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4737UR-1/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 1N4737UR-1/TR part is unused and in its original packaging.
Return procedure for 1N4737UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4737UR-1/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
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SMAZ12-13-F
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