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Microchip Technology 1N4737P/TR8
- Part No.:
- 1N4737P/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4737P/TR8.pdf
- Description:
- DIODE ZENER 7.5V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:9,472
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Product details
Overview
1N4737P/TR8 from Microsemi is a 1.0 W axial-lead silicon Zener diode with nominal Zener voltage of 7.5 V ±5%, 34 mA test current (IZT), 4.0 Ω dynamic impedance (ZZT), and maximum reverse leakage of 5 µA at 6.0 V. It operates from –65 °C to +150 °C and is used for precision voltage regulation in power supply reference, overvoltage protection, and biasing circuits.
For engineers reviewing the 1N4737P/TR8 datasheet, 1N4737P/TR8 pinout, 1N4737P/TR8 application, or 1N4737P/TR8 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (45 °C/W junction-to-lead), surge current rating (605 mA), RoHS-compliant "e3" plating, and DO-41 package compatibility with standard through-hole PCB layouts.
Technical Context
This device functions as a two-terminal voltage reference by operating in reverse breakdown with controlled dynamic impedance and low knee impedance (121 Ω at 0.5 mA). Its Zener voltage exhibits a temperature coefficient near zero (≈0 mV/°C) due to its 7.5 V rating - positioned at the crossover point where TC shifts from negative to positive.
The DO-41 plastic package delivers 45 °C/W junction-to-lead thermal resistance at 3/8″ lead length, enabling stable 1.0 W dissipation up to 105 °C lead temperature. It meets IPC/JEDEC J-STD-020B Level 1 moisture sensitivity and is rated for 260 °C soldering (10 s max).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.5 V ±5% at 34 mA - defines stable regulation point under nominal bias conditions |
| Power Dissipation | 1.0 W at TL ≤ 105 °C - sets maximum continuous DC power handling with proper lead heatsinking |
| Dynamic Impedance (ZZT) | 4.0 Ω at IZT = 34 mA - determines output voltage variation under load current changes |
| Reverse Leakage (IR) | 5 µA max at VR = 6.0 V - ensures minimal quiescent current in standby regulation mode |
| Surge Current (ISM) | 605 mA peak (½-sine, 1/120 s) - supports transient overvoltage clamping without failure |
| Thermal Resistance | 45 °C/W junction-to-lead - enables thermal design using lead length as primary heat path |
| Operating Temperature | –65 °C to +150 °C - suitable for industrial, automotive under-hood, and aerospace environments |
Pinout & Package
DO-41 (JEDEC DO-204AL) plastic axial-lead package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte-tin plated per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reverse-biased reference terminal | Connected to circuit ground or lower potential node during Zener operation |
| Cathode | Zener regulation output terminal | Banded end; held at regulated 7.5 V above anode when reverse-biased above breakdown |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC 1N47xxA-compliant construction | Ensures mechanical and electrical interchangeability with legacy 1W Zener designs |
| Level 1 moisture sensitivity | Eliminates dry-pack requirement and bake-out prior to assembly |
| RoHS-compliant "e3" termination | Meets global environmental compliance without performance trade-offs |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Reduces handling precautions and eliminates need for ESD-protected workstations |
| Zero-TC Zener voltage (7.5 V) | Minimizes drift over temperature in precision reference applications |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in linear regulator ICs or discrete op-amp references. IC Role / Device Role / Timing Role: Provides fixed 7.5 V reference for error amplifier input. Use Value: Maintains ±0.375 V regulation window across temperature and line variations. |
Use Scenario: Protecting microcontroller I/O pins from transient voltage spikes on sensor lines. IC Role / Device Role / Timing Role: Shunts excess energy above 7.5 V to ground before damage occurs. Use Value: Limits clamping voltage to 7.5 V + ISM × ZZT, preventing latch-up in 3.3 V logic interfaces. |
| Bias Network Stabilizer | Current Source Setpoint |
Use Scenario: Establishing stable base-emitter voltage for BJT constant-current sources. IC Role / Device Role / Timing Role: Sets VBE offset in emitter-follower bias chains. Use Value: Compensates for transistor VBE drift via matched temperature coefficient at 7.5 V. |
Use Scenario: Defining reference voltage for LM317 adjustable regulator or discrete current mirror. IC Role / Device Role / Timing Role: Serves as precision voltage setpoint for current-setting resistor. Use Value: Enables 7.5 V / RSET current accuracy within ±5% over full operating temperature range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4737A | No "P" suffix → glass DO-35 package; higher thermal resistance (60 °C/W vs. 45 °C/W) | Lower power derating margin in high-temperature environments | Select only if legacy glass-body compatibility required |
| BZX55C7V5 | 0.5 W rating, 7.5 V ±5%, DO-35 package, 100 Ω ZZT - lower power and higher impedance | Not suitable for 1 W continuous regulation; limited surge capability | Use only in low-power signal-level references with <50 mA load |
Compared with 1N4737A and BZX55C7V5, the 1N4737P/TR8 offers superior thermal performance and surge robustness for 1 W applications, while maintaining identical Zener voltage and tolerance - making it the preferred choice for industrial power rails and protection circuits requiring reliability at elevated ambient temperatures.
Availability
1N4737P/TR8 is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and bias network stabilizer applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for 1N4737P/TR8 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 and mixed-signal components for aerospace, defense, and industrial markets.
The 1N4737P/TR8 belongs to Microsemi's legacy 1N47xxAP series of 1 W plastic Zener diodes, designed specifically for ruggedized voltage regulation in harsh-environment power systems where thermal stability and long-term parametric consistency are critical.
FAQ
What is the Zener voltage tolerance for 1N4737P/TR8?
The 1N4737P/TR8 has a nominal Zener voltage of 7.5 V with a ±5% tolerance, as indicated by the "A" suffix in its JEDEC designation. This means the actual measured VZ falls between 7.125 V and 7.875 V when tested at 34 mA and 25 °C lead temperature. The tolerance is guaranteed across the full operating temperature range of –65 °C to +150 °C.
Does 1N4737P/TR8 require dry packing before PCB assembly?
No, the 1N4737P/TR8 is moisture sensitivity level (MSL) 1 per IPC/JEDEC J-STD-020B, meaning it may be stored indefinitely at ambient conditions without baking or dry packing. This eliminates pre-assembly moisture mitigation steps and simplifies manufacturing logistics for high-volume production.
What is the maximum surge current rating for 1N4737P/TR8?
The 1N4737P/TR8 has a maximum non-repetitive surge current (ISM) of 605 mA, measured using a ½-sine wave pulse of 1/120 second duration at 25 °C ambient. This rating supports transient overvoltage suppression in power rails and interface protection circuits without permanent degradation.
Is 1N4737P/TR8 RoHS compliant?
Yes, the "e3" suffix in the full orderable part number confirms that the 1N4737P/TR8 uses RoHS-compliant matte-tin plating on its axial leads and meets EU Directive 2011/65/EU requirements. The device contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits.
How does the thermal resistance of 1N4737P/TR8 compare to glass-body variants?
The 1N4737P/TR8 has a junction-to-lead thermal resistance of 45 °C/W at 3/8″ (10 mm) lead length, which is significantly lower than the 60 °C/W typical for glass-body 1N4737A devices. This 25% improvement allows higher continuous power dissipation or operation at elevated ambient temperatures without exceeding junction limits.
1N4737P/TR8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- 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 ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AL (DO-41)
1N4737P/TR8 FAQ
1.How can I place an order for 1N4737P/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4737P/TR8 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 1N4737P/TR8 reliable?
The price and inventory of 1N4737P/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4737P/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4737P/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4737P/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4737P/TR8?
1N4737P/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4737P/TR8 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 1N4737P/TR8?
For technical support, including 1N4737P/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4737P/TR8 requirements.
6.How does Aetrix verify that 1N4737P/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4737P/TR8 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 1N4737P/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4737P/TR8?
All 1N4737P/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4737P/TR8, 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 1N4737P/TR8 part is unused and in its original packaging.
Return procedure for 1N4737P/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4737P/TR8 Tags
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MMBZ5240B-7-F
Diodes Incorporated
-
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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