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Microchip Technology 1N4738CPE3/TR12
- Part No.:
- 1N4738CPE3/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738CPE3/TR12.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:3,568
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Product details
Overview
1N4738CPE3/TR12 from Microsemi is a 8.2 V, ±2% tolerance, 1 W silicon Zener diode in DO-41 plastic package, rated for 31 mA test current and 550 mA maximum regulator current at 50°C, used for precision voltage reference and overvoltage protection in linear power supplies and analog signal conditioning circuits.
For engineers reviewing the 1N4738CPE3/TR12 datasheet, 1N4738CPE3/TR12 pinout, 1N4738CPE3/TR12 application, or 1N4738CPE3/TR12 equivalent, key selection factors include Zener voltage tolerance (±2%), dynamic impedance (4.5 Ω @ 31 mA), thermal resistance (45 °C/W junction-to-lead), reverse leakage (10 µA @ 6.6 V), and RoHS-compliant matte-tin plating.
Technical Context
This Zener operates in reverse breakdown to maintain stable voltage across varying load and temperature conditions. It features a sharp knee in the I-V curve verified by dual-point Zener impedance measurement per MicroNote 202, with 4.5 Ω dynamic impedance at 31 mA and 400 Ω knee impedance at 0.5 mA.
Designed for axial-lead mounting on FR4 PCBs with 1 oz copper, it delivers 1.0 W steady-state power at lead temperature <105°C (3/8" from body) or ambient <45°C, with thermal resistance of 105 °C/W junction-to-ambient under defined layout conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.2 V ±2% at 31 mA - ensures tight regulation for reference circuits requiring <±0.16 V deviation |
| Power Dissipation | 1.0 W at TL < 105°C - supports continuous operation in compact linear regulators without forced cooling |
| Dynamic Impedance (ZZT) | 4.5 Ω @ 31 mA - minimizes output voltage variation under load transients |
| Reverse Leakage (IR) | 10 µA @ 6.6 V - enables low-power standby regulation with negligible quiescent current loss |
| Thermal Resistance (RθJL) | 45 °C/W junction-to-lead - allows direct thermal path to PCB copper for reliable derating |
| Operating Temperature | –65°C to +150°C - qualified for industrial and automotive under-hood environments |
| Forward Voltage | 1.2 V max @ 200 mA - supports bidirectional clamping when used with series resistor |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded package with cathode indicated by band; terminals are anode and cathode; no internal circuitry beyond PN junction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Zener regulation terminal | Connected to higher potential during reverse bias; must be positive relative to anode for regulation |
| Anode (unbanded end) | Reference/return terminal | Common return node for regulated output; forms current path through series resistor |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance (C suffix) | Enables high-accuracy voltage references without post-calibration in analog sensor interfaces |
| RoHS-compliant matte-tin plating (e3 suffix) | Ensures solderability and reliability under Pb-free reflow profiles up to 260°C for 10 s |
| Moisture sensitivity Level 1 (J-STD-020B) | Eliminates dry-pack requirement and floor-life constraints for SMT assembly planning |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Reduces handling precautions and eliminates need for ESD-safe workstations in production |
| Plastic encapsulation (P suffix) | Provides lower thermal resistance vs. glass-body variants, improving power handling in confined spaces |
Applications
| Linear Power Supply Reference | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Stabilizing output of unregulated DC-DC converter feeding op-amp bias networks. IC Role / Device Role / Timing Role: Precision voltage reference providing 8.2 V reference for feedback divider. Use Value: ±2% tolerance ensures <±0.16 V drift over life, maintaining ADC full-scale accuracy. | Use Scenario: Protecting microcontroller I/O pins against transient surges on 5 V rail. IC Role / Device Role / Timing Role: Shunt clamp limiting voltage to 8.2 V before damage threshold of 12 V. Use Value: 550 mA peak regulator current handles 100 ms surges without degradation. |
| Analog Sensor Signal Conditioning | Industrial Current Loop Interface |
Use Scenario: Biasing thermistor bridge in 4–20 mA transmitter with stable excitation. IC Role / Device Role / Timing Role: Low-noise voltage reference for Wheatstone bridge excitation. Use Value: 4.5 Ω dynamic impedance prevents signal ripple coupling into bridge output. | Use Scenario: Providing isolated 8.2 V supply for loop-powered field device electronics. IC Role / Device Role / Timing Role: Primary shunt regulator establishing local VCC from 4–20 mA loop. Use Value: 1.0 W rating sustains continuous operation at 20 mA × 8.2 V = 164 mW with margin. |
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% for 1N4738CPE3/TR12 | Lower accuracy; suitable where cost priority outweighs reference stability | Select when ±0.41 V tolerance acceptable and RoHS not required |
| BZX55C8V2 | Same 8.2 V ±5%, DO-35 package, 500 mW rating, higher ZZT (10 Ω) | Lower power and higher impedance limit use in high-current or low-noise apps | Choose for space-constrained layouts where 1 W dissipation not needed |
Compared with 1N4738A and BZX55C8V2, the 1N4738CPE3/TR12 offers tighter tolerance and higher power handling, making it preferable for precision analog references and industrial power rails where long-term stability and thermal margin are critical.
Availability
1N4738CPE3/TR12 is available at Aetrix Electronics and suitable for linear power supplies, overvoltage protection circuits, analog sensor interfaces, and industrial current-loop transmitters requiring stable component supply and RoHS compliance.
Supply support for 1N4738CPE3/TR12 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 applications.
The 1N47xxAP series targets general-purpose and precision voltage regulation, emphasizing robustness, wide temperature operation, and compatibility with legacy JEDEC designs.
FAQ
What is the Zener voltage tolerance of the 1N4738CPE3/TR12?
The 1N4738CPE3/TR12 has a Zener voltage tolerance of ±2%, denoted by the "C" suffix in the part number. This means its nominal 8.2 V Zener voltage is guaranteed between 8.04 V and 8.36 V when measured at 31 mA test current and 25°C lead temperature, supporting high-accuracy voltage reference designs where tighter regulation is required than standard ±5% parts like the 1N4738A.
What does the "e3" and "TR12" suffix mean in 1N4738CPE3/TR12?
The "e3" suffix indicates RoHS-compliant matte-tin plating per J-STD-609, ensuring compatibility with lead-free soldering processes up to 260°C. The "TR12" denotes tape-and-reel packaging per EIA-296 standard, with 12,000 units per reel - optimized for automated SMT placement despite the DO-41 axial-leaded form factor, enabling high-volume manufacturing without manual handling.
What is the maximum regulator current for the 1N4738CPE3/TR12 at 50°C?
The 1N4738CPE3/TR12 supports a maximum regulator current (IZM) of 550 mA at 50°C ambient, as specified in the Electrical Characteristics table. This value reflects safe continuous operation under thermal derating conditions and is critical for sizing the series current-limiting resistor in shunt regulator configurations to avoid exceeding the 1.0 W power limit at elevated temperatures.
How does the DO-41 package of the 1N4738CPE3/TR12 affect thermal performance?
The DO-41 (DO-204AL) package of the 1N4738CPE3/TR12 provides a thermal resistance of 45 °C/W junction-to-lead at 3/8" lead length, significantly better than junction-to-ambient (105 °C/W on FR4). This enables effective heat conduction through leads to copper pours or chassis mounts, allowing sustained 1.0 W dissipation in well-designed layouts - unlike smaller packages such as DO-35 which cannot support equivalent power.
Is the 1N4738CPE3/TR12 suitable for ESD-sensitive applications?
Yes, the 1N4738CPE3/TR12 is nonsensitive to ESD per MIL-STD-750 Method 1020, meaning it withstands typical handling electrostatic discharges without parameter shift or failure. This eliminates the need for special ESD controls during board assembly or field service, simplifying logistics and reducing risk in industrial environments where static charge buildup is common.
1N4738CPE3/TR12 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/TR12 FAQ
1.How can I place an order for 1N4738CPE3/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738CPE3/TR12 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/TR12 reliable?
The price and inventory of 1N4738CPE3/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738CPE3/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4738CPE3/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738CPE3/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738CPE3/TR12?
1N4738CPE3/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738CPE3/TR12 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/TR12?
For technical support, including 1N4738CPE3/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738CPE3/TR12 requirements.
6.How does Aetrix verify that 1N4738CPE3/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4738CPE3/TR12 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/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4738CPE3/TR12?
All 1N4738CPE3/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738CPE3/TR12, 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/TR12 part is unused and in its original packaging.
Return procedure for 1N4738CPE3/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738CPE3/TR12 Tags
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Diodes Incorporated
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