My Inquiry
My Account
Microchip Technology 1N4738P/TR12
- Part No.:
- 1N4738P/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4738P/TR12.pdf
- Description:
- DIODE ZENER 8.2V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:4,834
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4738P/TR12 from Microsemi is a 1.0 W axial-lead silicon Zener diode with nominal zener voltage 8.2 V, ±5% tolerance (A suffix), 31 mA test current (IZT), 4.5 Ω dynamic impedance (ZZT @ IZT), and cathode band polarity marking. It regulates voltage in low-power reference and protection circuits across industrial power supplies and analog signal conditioning stages.
For engineers reviewing the 1N4738P/TR12 datasheet, 1N4738P/TR12 pinout, 1N4738P/TR12 application, or 1N4738P/TR12 equivalent, key selection criteria include zener voltage accuracy at 31 mA, thermal resistance of 45 °C/W (junction-to-lead), maximum regulator current of 550 mA at TA = 50 °C, and DO-41 package compatibility with through-hole PCB assembly.
Technical Context
This device operates in reverse-bias breakdown mode to maintain stable voltage across its terminals under varying load and temperature conditions. Its 8.2 V regulation point is defined at 31 mA test current with 4.5 Ω dynamic impedance, ensuring predictable voltage deviation under small-signal AC superposition.
The DO-41 plastic package provides Level 1 moisture sensitivity per J-STD-020B, eliminating dry-pack requirements, and achieves 45 °C/W junction-to-lead thermal resistance at 10 mm lead length-critical for sustained 1.0 W dissipation without forced cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (Vz) | 8.2 V ±5% at 31 mA - defines precise regulation threshold for feedback and clamping |
| Power Dissipation | 1.0 W at TL < 105 °C - sets maximum continuous DC power handling in lead-mounted configuration |
| Dynamic Impedance | 4.5 Ω @ 31 mA - determines small-signal voltage variation under load transients |
| Max Regulator Current | 550 mA at TA = 50 °C - establishes safe peak reverse current before thermal runaway |
| Thermal Resistance | 45 °C/W junction-to-lead - enables thermal design using standard 10 mm lead length mounting |
| Reverse Leakage | 10 μA @ 6.5 V - ensures minimal quiescent current in standby or high-impedance bias networks |
| Forward Voltage | 1.2 V max @ 200 mA - supports use as forward-conducting clamp or dual-mode protection element |
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, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node during Zener operation; forward conduction path when biased positively |
| Cathode | Banded end | Connected to higher-potential node during Zener regulation; defines polarity for voltage reference orientation |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N4738A series | Ensures cross-manufacturer interchangeability and standardized test conditions per industry baseline |
| Plastic encapsulation (P suffix) | Reduces thermal resistance vs. glass-body variants, improving power handling reliability in compact layouts |
| Level 1 moisture sensitivity | Eliminates dry-pack requirement and bake-out prior to reflow, reducing manufacturing overhead |
| RoHS-compliant option (e3 suffix) | Supports environmental compliance without performance trade-offs in standard 1W Zener applications |
| Nonsensitive to ESD | Withstands MIL-STD-750 Method 1020 testing-enables handling in non-EPA environments without added protection |
Applications
| Power Supply Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Stabilizing feedback voltage in linear regulators or switching converter error amplifiers. IC Role / Device Role / Timing Role: Provides precise 8.2 V reference for op-amp comparator inputs or TL431-like shunt regulator configurations. Use Value: Maintains ±5% regulation over 10–100 mA operating range, minimizing output drift due to line/load variation. | Use Scenario: Protecting microcontroller I/O pins from transient voltage spikes on sensor interfaces. IC Role / Device Role / Timing Role: Shunts excess energy above 8.2 V to ground, limiting voltage stress on downstream CMOS inputs. Use Value: Responds within nanoseconds to surges up to 550 mA, preventing latch-up or gate oxide damage. |
| Analog Signal Conditioning | Current Source Biasing |
Use Scenario: Setting fixed bias points in op-amp gain stages or precision ADC front-ends. IC Role / Device Role / Timing Role: Acts as low-noise, temperature-stable voltage node for resistor-divider networks driving amplifier inputs. Use Value: Delivers <10 μA leakage at 6.5 V, preserving high-impedance node integrity and minimizing offset error. | Use Scenario: Establishing constant-current source for LED drivers or sensor excitation circuits. IC Role / Device Role / Timing Role: Serves as stable voltage reference in conjunction with series pass transistor or current mirror topology. Use Value: Enables 1% current stability over -65 °C to +150 °C via predictable 8.2 V reference and low ZZT. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | No TR12 tape-and-reel packaging; bulk or ammo pack only | Lacks automated placement support; requires manual or vibratory feeding | Select 1N4738P/TR12 for SMT-line integration; choose 1N4738A for prototyping or low-volume hand assembly |
| MMBZ5231BS | SOT-23 surface-mount package; 8.2 V ±5%, 20 mA IZT, 30 Ω ZZT | Lower power rating (0.25 W), unsuitable for >250 mA continuous regulation | Use MMBZ5231BS where board space is constrained and power demand is ≤200 mW; retain 1N4738P/TR12 for 1W thermal robustness |
Compared with 1N4738A and MMBZ5231BS, the 1N4738P/TR12 offers superior thermal management (45 °C/W vs. >200 °C/W), higher surge current capability (550 mA vs. 150 mA), and tape-and-reel readiness-making it optimal for production-scale through-hole power regulation where reliability and manufacturability are prioritized.
Availability
1N4738P/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, analog sensor interfaces, and embedded system voltage references requiring stable component supply and JEDEC-standardized Zener performance.
Supply support for 1N4738P/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 1N4738P/TR12 belongs to Microsemi's legacy 1N47xxAP Zener diode family, engineered for stable voltage regulation in harsh-environment power systems where long-term parametric consistency and JEDEC compliance are mandatory.
FAQ
What is the zener voltage tolerance of the 1N4738P/TR12?
The 1N4738P/TR12 has a nominal zener voltage of 8.2 V with ±5% tolerance, as indicated by the "A" suffix in its part number per JEDEC registration. This means the actual measured Vz falls between 7.79 V and 8.61 V when tested at 31 mA and 25 °C lead temperature. The tolerance is guaranteed across the full operating temperature range of –65 °C to +150 °C, and applies to every unit shipped in the 1N4738P/TR12 reel.
Does the 1N4738P/TR12 require dry packing before PCB assembly?
No, the 1N4738P/TR12 does not require dry packing. Its DO-41 plastic package is rated Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it may be stored indefinitely at ambient conditions without desiccant or baking. This eliminates pre-reflow bake steps and simplifies logistics for high-mix manufacturing lines handling the 1N4738P/TR12.
What is the maximum steady-state current the 1N4738P/TR12 can regulate continuously?
The 1N4738P/TR12 supports a maximum regulator current (IZM) of 550 mA at an ambient temperature of 50 °C when mounted on FR4 with specified copper pad geometry. At 25 °C ambient, derating curves allow up to 730 mA, but thermal design must ensure junction temperature remains below 150 °C. Exceeding IZM risks irreversible degradation of the 1N4738P/TR12's zener characteristics.
How does the "TR12" suffix affect the 1N4738P/TR12 compared to standard 1N4738AP?
"TR12" denotes EIA-296 standard tape-and-reel packaging with 12 mm tape width and 10,000 units per reel-optimized for automated pick-and-place equipment. Unlike bulk or ammo-pack versions of 1N4738AP, the 1N4738P/TR12 enables direct integration into SMT production lines without repackaging, preserving moisture sensitivity compliance and traceability throughout the 1N4738P/TR12 supply chain.
Can the 1N4738P/TR12 be used in forward-bias applications?
Yes, the 1N4738P/TR12 functions as a standard silicon diode in forward bias, with a maximum forward voltage of 1.2 V at 200 mA. While not optimized for rectification, this capability allows dual-use designs-such as bidirectional clamping or combined reference/forward-protection circuits-without adding discrete diodes. However, forward conduction should remain within SOA limits to avoid thermal overstress of the 1N4738P/TR12.
1N4738P/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:
- ±10%
- 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)
1N4738P/TR12 FAQ
1.How can I place an order for 1N4738P/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4738P/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 1N4738P/TR12 reliable?
The price and inventory of 1N4738P/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4738P/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4738P/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4738P/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4738P/TR12?
1N4738P/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4738P/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 1N4738P/TR12?
For technical support, including 1N4738P/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4738P/TR12 requirements.
6.How does Aetrix verify that 1N4738P/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4738P/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 1N4738P/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4738P/TR12?
All 1N4738P/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4738P/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 1N4738P/TR12 part is unused and in its original packaging.
Return procedure for 1N4738P/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4738P/TR12 Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
