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Microchip Technology 1N4738CP/TR12
- Part No.:
- 1N4738CP/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738CP/TR12.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:8,863
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Product details
Overview
1N4738CP/TR12 from Microsemi is a 1.0 W axial-lead silicon Zener diode with nominal zener voltage 8.2 V ±5%, 31 mA test current (IZT), 4.5 Ω dynamic impedance (ZZT), and maximum regulator current 550 mA at TA = 50°C. It operates from –65°C to +150°C and regulates voltage in power supply reference, overvoltage protection, and voltage-clamping circuits.
For engineers reviewing the 1N4738CP/TR12 datasheet, 1N4738CP/TR12 pinout, 1N4738CP/TR12 application, or 1N4738CP/TR12 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (45°C/W junction-to-lead), surge current rating (550 mA), RoHS-compliant "e3" plating, and DO-41 package compatibility with standard axial-lead PCB layouts.
Technical Context
This device functions as a precision voltage reference by operating in reverse breakdown, where its zener voltage remains stable across 10–550 mA regulation current and –65°C to +150°C ambient range. Its 4.5 Ω dynamic impedance ensures low output variation under load transients.
The DO-41 plastic package provides Level 1 moisture sensitivity (no dry pack required), UL94V-0 epoxy body, and tin-lead or RoHS-compliant matte-tin plating. Cathode polarity is marked by a band; operation requires cathode-positive bias for regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.2 V ±5% at IZT = 31 mA - defines stable regulation point for feedback loops and reference rails |
| Power Dissipation | 1.0 W at TL < 105°C (3/8″ lead length) - sets maximum continuous DC power before thermal derating |
| Dynamic Impedance (ZZT) | 4.5 Ω at IZT = 31 mA - determines output voltage deviation under changing load current |
| Max Regulator Current (IZM) | 550 mA at TA = 50°C - limits safe reverse-bias current in clamping or shunt-regulator topologies |
| Thermal Resistance | 45°C/W junction-to-lead - enables thermal design using lead conduction path, not board copper |
| Reverse Leakage | 10 μA max at VR = 6 V - ensures minimal quiescent current in standby or high-impedance sensing nodes |
| Surge Current (ISM) | 550 mA (½-sine, 1/120 s) - supports transient overvoltage suppression without failure |
Pinout & Package
DO-41 (DO-204AL) plastic axial-lead 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-bias reference node | Connected to lower-potential rail; forms shunt path when cathode voltage exceeds 8.2 V |
| Cathode | Zener regulation output | Banded end; connected to regulated voltage node; must be held >8.2 V above anode for conduction |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N4738A series | Ensures cross-manufacturer interchangeability and standardized test conditions per JESD24 |
| 5% zener voltage tolerance (A suffix) | Guarantees regulation within ±0.41 V of 8.2 V at 31 mA, supporting mid-precision analog references |
| Plastic P-suffix construction | Reduces thermal resistance vs. glass-body variants, improving power handling in compact layouts |
| RoHS-compliant "e3" plating | Meets EU Directive 2011/65/EU with annealed matte-tin finish, compatible with Pb-free reflow |
| Level 1 moisture sensitivity | Eliminates dry-pack requirement and floor-life constraints, simplifying SMT and manual assembly logistics |
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: Shunt voltage reference providing precise 8.2 V setpoint for error amplifier input. Use Value: Maintains ±5% output regulation across 10–550 mA load range and –65°C to +150°C, reducing need for trimming. | Use Scenario: Clamping transient spikes on 5 V or 12 V DC rails caused by inductive switching or ESD events. IC Role / Device Role / Timing Role: Passive crowbar element that conducts above 8.2 V to divert excess energy to ground. Use Value: Withstands 550 mA surge current (½-sine, 1/120 s), protecting downstream logic and analog circuitry. |
| Voltage-Level Translation | Signal Conditioning Clamp |
Use Scenario: Biasing op-amp inputs or setting logic thresholds in mixed-voltage systems (e.g., 3.3 V MCU interfacing with 8 V sensor). IC Role / Device Role / Timing Role: Fixed-voltage clamp limiting signal swing to 8.2 V while blocking reverse current. Use Value: Low 4.5 Ω dynamic impedance minimizes distortion during fast-rising edge clamping. | Use Scenario: Protecting ADC inputs or comparator reference pins from out-of-range analog signals. IC Role / Device Role / Timing Role: Precision limiter preventing damage or latch-up by capping voltage at 8.2 V. Use Value: 10 μA max leakage at 6 V ensures negligible loading on high-impedance sensor outputs. |
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 "P" suffix indicates glass-body construction; higher thermal resistance (105°C/W junction-to-ambient vs. 45°C/W junction-to-lead) | Less suitable for high-power-density designs requiring lead-conducted heat removal | Select 1N4738CP/TR12 when DO-41 plastic package, lower thermal resistance, or tape-and-reel delivery is required |
| MMBZ5231BS | SOT-23 surface-mount package; 8.2 V ±5%; 20 mA IZT; 30 Ω ZZT - higher impedance and lower power (250 mW) | Not interchangeable in axial-lead footprints; limited to low-current, space-constrained PCBs | Choose MMBZ5231BS only for automated SMT assembly where board area is critical and regulation current ≤20 mA |
Compared with 1N4738A and MMBZ5231BS, the 1N4738CP/TR12 delivers superior thermal performance via DO-41 lead conduction, higher surge current capability (550 mA), and tape-and-reel packaging for automated insertion-making it optimal for industrial power supplies and ruggedized clamping designs.
Availability
1N4738CP/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and analog reference designs requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.
Supply support for 1N4738CP/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) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and timing components for aerospace, defense, and industrial markets.
The 1N47xxAP series was designed specifically for general-purpose voltage regulation in cost-sensitive, high-volume applications where JEDEC-standardized performance, thermal robustness, and moisture-insensitive packaging are essential.
FAQ
What is the zener voltage tolerance of the 1N4738CP/TR12?
The 1N4738CP/TR12 has a nominal zener voltage of 8.2 V with a ±5% tolerance, as indicated by the "A" suffix in the part number. This means the actual measured VZ at 31 mA test current falls between 7.79 V and 8.61 V under standard test conditions (TL = 25°C ±8°C, 90 seconds after current application). The tolerance is guaranteed per JEDEC registration and applies to all units in the 1N4738CP/TR12 lot.
Does the 1N4738CP/TR12 require dry packing before PCB assembly?
No, the 1N4738CP/TR12 does not require dry packing. Its DO-41 plastic package is rated IPC/JEDEC J-STD-020B Level 1 for moisture sensitivity, meaning it has unlimited floor life at standard ambient conditions (≤30°C/60% RH) and can be assembled directly without baking or dry storage. This simplifies inventory handling and eliminates moisture-related defects during reflow or wave soldering.
What is the maximum steady-state power dissipation for the 1N4738CP/TR12?
The 1N4738CP/TR12 is rated for 1.0 W steady-state power dissipation at lead temperature (TL) < 105°C with 3/8″ (10 mm) lead length from the body, or at ambient temperature (TA) < 45°C when mounted on an FR4 PCB with specified copper pad geometry. Power must be derated linearly above these temperatures per Figure 1 in the Microsemi datasheet; at TA = 70°C, maximum allowable power drops to approximately 0.75 W.
How is polarity marked on the 1N4738CP/TR12?
The 1N4738CP/TR12 uses a cathode band - a single colored ring near one end of the DO-41 cylindrical body - to indicate polarity. The banded end is the cathode and must be biased positive relative to the anode (unbanded end) for proper zener regulation. Reversing polarity subjects the device to forward conduction (VF ≤ 1.2 V @ 200 mA), which does not provide voltage regulation and may cause unintended circuit behavior.
What does the "TR12" suffix mean in 1N4738CP/TR12?
The "TR12" suffix in 1N4738CP/TR12 indicates tape-and-reel packaging per EIA-296 standard, with 12,000 units per reel. The "TR" denotes tape-and-reel format, and "12" specifies the reel quantity. This configuration supports automated pick-and-place assembly and is distinct from bulk or ammo-pack options. The base device remains identical to 1N4738CP in electrical and thermal specifications.
1N4738CP/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)
1N4738CP/TR12 FAQ
1.How can I place an order for 1N4738CP/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738CP/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 1N4738CP/TR12 reliable?
The price and inventory of 1N4738CP/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738CP/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4738CP/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738CP/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738CP/TR12?
1N4738CP/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738CP/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 1N4738CP/TR12?
For technical support, including 1N4738CP/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738CP/TR12 requirements.
6.How does Aetrix verify that 1N4738CP/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4738CP/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 1N4738CP/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4738CP/TR12?
All 1N4738CP/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738CP/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 1N4738CP/TR12 part is unused and in its original packaging.
Return procedure for 1N4738CP/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738CP/TR12 Tags
-
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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