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Microchip Technology 1N4738CP/TR8
- Part No.:
- 1N4738CP/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738CP/TR8.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:6,007
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Product details
Overview
1N4738CP/TR8 from Microsemi is a 1.0 W, 8.2 V ±5% axial-lead Zener diode in DO-41 plastic package, rated for 31 mA test current, 4.5 Ω dynamic impedance at IZT, and 6 mA maximum reverse leakage at 6.6 V. It delivers stable voltage regulation in power supply reference and overvoltage protection circuits across -65°C to +150°C.
For engineers reviewing the 1N4738CP/TR8 datasheet, 1N4738CP/TR8 pinout, 1N4738CP/TR8 application, or 1N4738CP/TR8 equivalent, key selection factors include its 8.2 V nominal Zener voltage, 1.0 W power rating at 25°C with 45°C/W junction-to-lead thermal resistance, RoHS-compliant matte-tin plating, and tape-and-reel packaging (TR8) for automated assembly.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain a stable 8.2 V reference across a wide current range (1–550 mA), with sharp knee characteristics verified by dual-point Zener impedance measurement per MicroNote 202. Its DO-41 plastic encapsulation provides Level 1 moisture sensitivity (no dry pack required) and lower thermal resistance than glass-body variants.
The device exhibits a typical temperature coefficient near +3.5 mV/°C (per Figure 3), enabling predictable drift compensation in precision references. It supports steady-state dissipation of 1.0 W at lead temperature <105°C (3/8" from body) or ambient <45°C on FR4 with defined copper pad geometry, and withstands 260°C soldering for 10 s.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.2 V ±5% at IZT = 31 mA - defines precise regulation point for feedback loops and reference rails |
| Power Dissipation | 1.0 W at TL ≤ 105°C - sets maximum continuous thermal load under lead-heatsink conditions |
| Dynamic Impedance | 4.5 Ω at IZT = 31 mA - determines output voltage stability under varying load current |
| Reverse Leakage | 6 μA max at VR = 6.6 V - ensures low quiescent current in standby or high-impedance bias networks |
| Thermal Resistance | 45°C/W junction-to-lead - enables thermal design using lead as primary heat path, not PCB copper |
| Surge Current | 500 mA peak (½-sine, 1/120 s) - supports transient overvoltage clamping without degradation |
| Forward Voltage | 1.2 V max at IF = 200 mA - relevant for polarity-check or series-switch applications |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded package with cathode indicated by color 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; regulates voltage referenced to this terminal |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N4738A series | Ensures cross-manufacturer compatibility and standardized test conditions per JESD24 |
| Plastic P-suffix construction | Delivers 45°C/W junction-to-lead thermal resistance-superior to glass-body G-suffix alternatives |
| RoHS-compliant "e3" option | Meets EU Directive 2011/65/EU with annealed matte-tin plating, no lead or hazardous substances |
| Tape-and-reel packaging (TR8) | Enables high-speed pick-and-place assembly with EIA-296 standard carrier tape and 8 mm pocket pitch |
| Level 1 moisture sensitivity | Eliminates dry-pack requirement and floor-life constraints per IPC/JEDEC J-STD-020B |
Applications
| Power Supply Reference | Overvoltage Protection |
|---|---|
Use Scenario: Stabilizing feedback voltage in linear regulator ICs or discrete transistor-based regulators. IC Role / Device Role / Timing Role: Provides fixed 8.2 V reference for error amplifier input, replacing higher-cost precision references where ±5% tolerance suffices. Use Value: Enables cost-effective, thermally robust regulation with 4.5 Ω dynamic impedance limiting output variation under load transients. | Use Scenario: Clamping transient spikes on DC rails in industrial control I/O modules. IC Role / Device Role / Timing Role: Shunts excess energy to ground when rail voltage exceeds 8.2 V, protecting downstream logic and analog circuitry. Use Value: Withstands 500 mA surge current and maintains regulation integrity after repeated 1/120 s transients. |
| Signal Level Shifting | Current Source Biasing |
Use Scenario: Generating stable bias points for op-amp input stages in sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Acts as two-terminal voltage source to set common-mode voltage or offset in differential amplifiers. Use Value: Low 6 μA leakage at 6.6 V minimizes error in high-impedance bias networks, preserving signal fidelity. | Use Scenario: Establishing constant-current sink for LED driver or phototransistor interface circuits. IC Role / Device Role / Timing Role: Functions as voltage-controlled current source when combined with series resistor (e.g., 1 kΩ for ~7.4 mA). Use Value: Stable 8.2 V Zener voltage ensures repeatable current across -65°C to +150°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | No TR8 tape-and-reel packaging; bulk or ammo pack only; same electrical specs and DO-41 package | Not suitable for automated SMT placement; requires manual or vibratory bowl feeding | Select 1N4738CP/TR8 for production lines requiring reel-fed assembly; choose 1N4738A for prototyping or low-volume hand-soldering |
| MMBZ5231BS | SOT-23 surface-mount package; 8.2 V ±5%, 225 mW rating; 30 Ω ZZT; different thermal path and surge capability | Designed for space-constrained PCBs; unsuitable for >225 mW continuous dissipation or high-energy transients | Use MMBZ5231BS only where board area is critical and power/thermal demands are lower; retain 1N4738CP/TR8 for 1 W regulation or ruggedized designs |
Compared with 1N4738A and MMBZ5231BS, the 1N4738CP/TR8 uniquely combines 1 W power handling, DO-41 mechanical robustness, tape-and-reel automation readiness, and proven surge resilience-making it optimal for industrial power rails and legacy-compatible designs where leaded reliability is prioritized.
Availability
1N4738CP/TR8 is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and sensor bias networks requiring stable component supply, long-term lifecycle support, and RoHS-compliant procurement.
Supply support for 1N4738CP/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, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N4738CP/TR8 belongs to Microsemi's legacy 1N47xxAP Zener diode family, engineered for general-purpose voltage regulation with emphasis on thermal performance, JEDEC compliance, and manufacturability in high-volume electronics assembly.
FAQ
What is the Zener voltage tolerance of the 1N4738CP/TR8?
The 1N4738CP/TR8 has a nominal Zener voltage of 8.2 V with a ±5% tolerance, as indicated by the "A" suffix in its JEDEC designation. This means the actual measured VZ falls between 7.79 V and 8.61 V at 31 mA test current and 25°C lead temperature. The tolerance is guaranteed per JEDEC registration and applies across the full operating temperature range.
Does the 1N4738CP/TR8 require dry packing before reflow?
No, the 1N4738CP/TR8 does not require dry packing. Its DO-41 plastic package is rated Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it has unlimited floor life and may be used directly from sealed packaging without baking or humidity-controlled storage prior to soldering.
What is the maximum surge current rating for the 1N4738CP/TR8?
The 1N4738CP/TR8 is rated for a maximum non-repetitive reverse surge current (ISM) of 500 mA, measured using a ½-sine wave pulse of 1/120 second duration at 25°C ambient. This rating supports transient clamping in power supply inputs and I/O protection circuits without permanent parameter shift.
Can the 1N4738CP/TR8 be used in surface-mount designs?
No, the 1N4738CP/TR8 is an axial-leaded DO-41 device and is not compatible with surface-mount assembly. For SMT equivalents, Microsemi offers the SMAJ4738A and MLL4738A in DO-214AC and SOD-123 packages respectively-both share the same 8.2 V Zener voltage but differ in power rating, thermal resistance, and mounting method.
What does the "TR8" suffix mean in 1N4738CP/TR8?
"TR8" indicates tape-and-reel packaging per EIA-296 standard, with 8 mm pocket pitch and orientation optimized for automated pick-and-place equipment. The "P" denotes plastic DO-41 construction, and "e3" (implied in RoHS-compliant versions) specifies matte-tin plating. TR8 enables high-throughput assembly while maintaining full electrical and thermal specifications of the base 1N4738A device.
1N4738CP/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):
- 8.2 V
- Tolerance:
- ±2%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 4.5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 6 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)
1N4738CP/TR8 FAQ
1.How can I place an order for 1N4738CP/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738CP/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 1N4738CP/TR8 reliable?
The price and inventory of 1N4738CP/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738CP/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4738CP/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738CP/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738CP/TR8?
1N4738CP/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738CP/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 1N4738CP/TR8?
For technical support, including 1N4738CP/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738CP/TR8 requirements.
6.How does Aetrix verify that 1N4738CP/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4738CP/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 1N4738CP/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4738CP/TR8?
All 1N4738CP/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738CP/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 1N4738CP/TR8 part is unused and in its original packaging.
Return procedure for 1N4738CP/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738CP/TR8 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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