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Microchip Technology 1N4738CPE3/TR8
- Part No.:
- 1N4738CPE3/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738CPE3/TR8.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:7,924
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Product details
Overview
1N4738CPE3/TR8 from Microsemi is a 1.0 W, 8.2 V ±2% tolerance silicon Zener diode in DO-41 plastic package, designed for precision voltage regulation in power supply feedback loops, reference circuits, and overvoltage protection. It operates across –65°C to +150°C, delivers 31 mA test current (IZT), and exhibits 4.5 Ω dynamic impedance at IZT.
For engineers reviewing the 1N4738CPE3/TR8 datasheet, 1N4738CPE3/TR8 pinout, 1N4738CPE3/TR8 application, or 1N4738CPE3/TR8 equivalent, key selection criteria include its tight ±2% Zener voltage tolerance (C suffix), RoHS-compliant matte-tin plating (e3), tape-and-reel packaging (TR8), and verified thermal resistance of 45°C/W junction-to-lead at 10 mm lead length.
Technical Context
This Zener diode functions as a two-terminal shunt regulator, maintaining stable output voltage by conducting reverse current above its specified breakdown threshold. Its sharp knee characteristic-validated by dual-point Zener impedance measurement per MicroNote 202-ensures reliable regulation under varying load and temperature conditions.
The device uses void-free thermosetting epoxy encapsulation (UL94V-0 rated) with cathode band polarity marking, tin-lead or RoHS-compliant annealed matte-tin terminals, and is moisture-sensitive Level 1 per IPC/JEDEC J-STD-020B-no dry pack required prior to soldering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (Vz) | 8.2 V ±2% at 31 mA - enables precise reference generation in analog feedback paths |
| Power Dissipation | 1.0 W at TL < 105°C - supports continuous regulation in compact linear supplies |
| Dynamic Impedance (ZZT) | 4.5 Ω at IZT = 31 mA - ensures low output voltage variation under load transients |
| Max Reverse Current (IR) | 10 μA at VR = 6 V - guarantees minimal leakage in high-impedance bias networks |
| Thermal Resistance | 45°C/W junction-to-lead - allows direct thermal coupling to PCB copper for stable operation |
| Operating Temperature | –65°C to +150°C - suitable for industrial and automotive under-hood environments |
| Forward Voltage | ≤1.2 V at 200 mA - supports bidirectional clamping when used with series resistor |
Pinout & Package
DO-41 (DO-204AL) axial-leaded plastic package with cathode indicated by colored 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 | Reverse-biased input terminal | Connected to lower-potential node; conducts only during Zener breakdown |
| Cathode | Regulated output terminal | Banded end; held at stable Vz above anode potential during regulation |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance (C suffix) | Reduces calibration drift in precision references without external trimming |
| RoHS-compliant "e3" termination | Enables compliance with environmental directives without sacrificing solderability |
| Tape-and-reel packaging ("TR8") | Supports automated SMT placement despite axial-leaded form factor |
| Moisture sensitivity Level 1 | Eliminates pre-bake requirement before reflow, reducing manufacturing overhead |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Permits handling in standard assembly environments without special grounding |
Applications
| Power Supply Feedback | Overvoltage Clamp |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or buck-derived DC/DC converters. IC Role / Device Role / Timing Role: Shunt reference element in optocoupler feedback loop. Use Value: Maintains ±2% output accuracy across line/load/temperature with no active compensation. | Use Scenario: Protecting microcontroller I/O pins from transient voltage spikes. IC Role / Device Role / Timing Role: Bidirectional clamp referenced to ground or rail. Use Value: Limits voltage to 8.2 V with <10 μA leakage below 6 V, preserving signal integrity. |
| Voltage Reference | Current Source Bias |
Use Scenario: Providing stable bias for op-amp comparators or ADC reference dividers. IC Role / Device Role / Timing Role: Low-drift, low-noise DC reference node. Use Value: Delivers 8.2 V with 4.5 Ω dynamic impedance, minimizing error from source impedance mismatch. | Use Scenario: Setting constant current in LED driver or sensor excitation circuits. IC Role / Device Role / Timing Role: Fixed-voltage node for resistor-based current programming. Use Value: Enables predictable current setpoint (e.g., 8.2 mA with 1 kΩ) across 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 |
|---|---|---|---|
| 1N4738A | Same 8.2 V nominal, but ±5% tolerance (A suffix) vs. ±2% (C suffix) | Less suitable for precision references requiring tight initial accuracy | Select 1N4738CPE3/TR8 when ±2% tolerance is mandatory for system-level calibration |
| BZX55C8V2 | Same 8.2 V ±2%, but 500 mW rating and DO-35 package | Limited to lower-power applications; higher thermal resistance (500°C/W typical) | Choose 1N4738CPE3/TR8 for 1 W dissipation needs and superior thermal performance in DO-41 |
Compared with 1N4738A and BZX55C8V2, the 1N4738CPE3/TR8 offers tighter voltage tolerance than the former and higher power handling plus lower thermal resistance than the latter-making it optimal for industrial-grade 1 W reference and clamp designs where accuracy and thermal stability are jointly critical.
Availability
1N4738CPE3/TR8 is available at Aetrix Electronics and suitable for power supply feedback, overvoltage protection, and precision voltage reference applications requiring stable component supply and full RoHS compliance.
Supply support for 1N4738CPE3/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 1N47xxAP series was developed to deliver JEDEC-standardized, high-stability Zener regulation in ruggedized plastic packages for mission-critical power and reference subsystems.
FAQ
What is the Zener voltage tolerance of the 1N4738CPE3/TR8?
The 1N4738CPE3/TR8 has a Zener voltage tolerance of ±2%, indicated by the "C" suffix in its part number. This means its measured breakdown voltage at 31 mA test current falls within 8.036 V to 8.364 V at 25°C lead temperature. This tighter tolerance supports precision applications where calibration drift must be minimized without post-manufacturing trimming.
What does the "e3" suffix mean in 1N4738CPE3/TR8?
"e3" denotes RoHS-compliant matte-tin plating on the leads of the 1N4738CPE3/TR8, replacing traditional tin-lead finishes. This plating meets JEDEC J-STD-020B solderability requirements and supports lead-free reflow profiles up to 260°C for 10 seconds. The "e3" designation confirms full compliance with EU RoHS Directive 2011/65/EU and related environmental standards.
What is the maximum power dissipation of the 1N4738CPE3/TR8?
The 1N4738CPE3/TR8 is rated for 1.0 watt steady-state power dissipation at a lead temperature (TL) below 105°C with 10 mm lead length from the body, or at ambient temperature (TA) below 45°C when mounted on FR4 with specified copper pads. Derating is required above these temperatures per Figure 1 in the Microsemi datasheet, reaching zero dissipation at TL = 175°C.
How is polarity marked on the 1N4738CPE3/TR8?
The 1N4738CPE3/TR8 uses a cathode band-typically a single dark-colored stripe near one end-to indicate polarity. For proper Zener regulation, the banded end (cathode) must be held at a higher potential than the unmarked end (anode). Forward conduction occurs when the unmarked end is positive relative to the banded end, with VF ≤1.2 V at 200 mA.
What packaging format does "TR8" indicate for the 1N4738CPE3/TR8?
"TR8" specifies tape-and-reel packaging per EIA-296 standard, with 8 mm carrier tape width and component orientation optimized for automated pick-and-place equipment. This format enables high-throughput assembly while preserving the axial-leaded DO-41 mechanical configuration. Each reel contains standard quantities aligned with industry logistics requirements for production-scale deployment.
1N4738CPE3/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)
1N4738CPE3/TR8 FAQ
1.How can I place an order for 1N4738CPE3/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738CPE3/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 1N4738CPE3/TR8 reliable?
The price and inventory of 1N4738CPE3/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738CPE3/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4738CPE3/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738CPE3/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738CPE3/TR8?
1N4738CPE3/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738CPE3/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 1N4738CPE3/TR8?
For technical support, including 1N4738CPE3/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738CPE3/TR8 requirements.
6.How does Aetrix verify that 1N4738CPE3/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4738CPE3/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 1N4738CPE3/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4738CPE3/TR8?
All 1N4738CPE3/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738CPE3/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 1N4738CPE3/TR8 part is unused and in its original packaging.
Return procedure for 1N4738CPE3/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738CPE3/TR8 Tags
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MMBZ5240B-7-F
Diodes Incorporated
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