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Microchip Technology 1N748C-1/TR
- Part No.:
- 1N748C-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N748C-1/TR.pdf
- Description:
- DIODE ZENER 3.9V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:9,543
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Product details
Overview
1N748C-1/TR from Microsemi is a 500 mW, 3.9 V ±2% tolerance silicon Zener diode in DO-35 (DO-204AH) axial-glass package, qualified to JANTX level per MIL-PRF-19500/127, with dynamic impedance of 20 Ω at 30 mA and temperature coefficient of -0.060 %/°C - used for precision voltage regulation in military-grade power supply reference circuits.
For engineers reviewing the 1N748C-1/TR datasheet, 1N748C-1/TR pinout, 1N748C-1/TR application, or 1N748C-1/TR equivalent, key selection criteria include Zener voltage tolerance (±2%), junction-to-lead thermal resistance (250 °C/W), RoHS compliance status, MIL-qualified reliability level, and DO-35 mechanical mounting compatibility.
Technical Context
This device operates as a reverse-biased voltage reference with a nominal Zener voltage of 3.9 V at 30 mA test current (IZT), exhibiting low dynamic impedance (20 Ω) and stable regulation across -65 °C to +175 °C operating temperature range. Its metallurgically bonded construction ensures robust thermal performance and radiation hardness per MicroNote 050.
The 1N748C-1/TR is part of the JEDEC-registered 1N746A–1N759A series, where the "C" suffix denotes ±2% voltage tolerance and "TR" indicates EIA-296 tape-and-reel packaging. It is not a surface-mount device - it uses axial leads with cathode band marking and requires lead-forming for PCB through-hole mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 3.9 V at IZT = 30 mA - defines precise regulation point for low-voltage reference design |
| Zener Tolerance | ±2% - tighter than standard ±5%, enabling higher accuracy in feedback loops |
| Power Dissipation | 500 mW @ TL = 50°C (0.375″ lead length) - sets maximum continuous DC power handling |
| Dynamic Impedance (ZZT) | 20 Ω @ IZT = 30 mA - determines output voltage stability under load variation |
| Temp. Coefficient (αVZ) | -0.060 %/°C @ 25°C - quantifies voltage drift with temperature in critical analog circuits |
| Reverse Leakage (IR) | 2 µA @ VR = 1.0 V - confirms low off-state current for standby power integrity |
| Max Regulator Current (IZM) | 30 mA - limits safe DC operating current before thermal runaway risk |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed axial-leaded glass package with cathode indicated by a single black 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 positively |
| Cathode | Banded end | Connected to higher-potential node during Zener operation; defines regulation polarity |
Key Features
| Feature | Design Value |
|---|---|
| JANTX qualification per MIL-PRF-19500/127 | Validated reliability for aerospace and defense systems requiring extended temperature and life testing |
| Metallurgical bond construction | Enables stable electrical parameters and radiation hardness without epoxy-induced degradation |
| Low capacitance & ESD insensitivity | Minimizes signal coupling in high-frequency references; immune to MIL-STD-750 method 1020 ESD stress |
| RoHS-compliant option (e3) | Commercial-grade version available with annealed matte-tin plating meeting EU Directive 2011/65/EU |
Applications
| Avionics Power Reference | Military Radio Bias Supply |
|---|---|
Use Scenario: Providing stable 3.9 V reference for ADC voltage scaling and op-amp biasing in airborne navigation units. IC Role / Device Role / Timing Role: Precision shunt voltage reference maintaining regulation despite wide ambient (-55°C to +125°C) and transient load conditions. Use Value: ±2% tolerance and -0.060 %/°C TC ensure <±30 mV total drift over full military temperature range. | Use Scenario: Setting bias point for RF power amplifier stages in handheld tactical radios operating under vibration and thermal cycling. IC Role / Device Role / Timing Role: Low-noise Zener regulator supplying clean gate/base bias to discrete transistors in PA driver chains. Use Value: 20 Ω dynamic impedance suppresses ripple-induced distortion in sensitive analog front-end circuitry. |
| Spacecraft Sensor Interface | Industrial PLC Analog Input |
Use Scenario: Calibrating thermistor-based temperature sensors on satellite subsystems exposed to ionizing radiation. IC Role / Device Role / Timing Role: Radiation-hardened voltage reference compensating for sensor nonlinearity in telemetry conditioning circuits. Use Value: Inherent radiation hardness (MicroNote 050) eliminates need for shielding or derating in LEO missions. | Use Scenario: Generating stable reference for 4–20 mA loop-powered transmitters in factory automation control cabinets. IC Role / Device Role / Timing Role: Primary shunt regulator establishing excitation voltage for precision current-sense resistors and instrumentation amplifiers. Use Value: 500 mW power rating supports long-term operation at elevated ambient temperatures (up to +75°C on FR4 board). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N748A-1/TR | ±5% Zener tolerance vs. ±2% for 1N748C-1/TR; otherwise identical electrical and mechanical specs | Suitable where cost sensitivity outweighs precision requirement; less stable over temperature | Select 1N748A-1/TR only if system-level calibration compensates for wider VZ spread |
| MMBZ5226BS-7-F | Surface-mount SOD-123 package; ±5% tolerance; 3.9 V nominal; 225 mW rating; no MIL qualification | Used in commercial consumer electronics; lacks radiation hardness and extended temp range | Choose MMBZ5226BS-7-F only for space-constrained, non-military designs with relaxed reliability requirements |
Compared with 1N748A-1/TR and MMBZ5226BS-7-F, the 1N748C-1/TR delivers superior voltage accuracy and military-grade reliability at the cost of larger axial footprint and higher procurement complexity - optimal for regulated power rails where long-term stability and environmental resilience are mandatory.
Availability
1N748C-1/TR is available at Aetrix Electronics and suitable for avionics power reference, military radio bias supply, and spacecraft sensor interface applications requiring stable component supply across extended product lifecycles.
Supply support for 1N748C-1/TR 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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and aerospace-grade components.
The 1N748C-1/TR belongs to Microsemi's legacy MIL-PRF-19500/127-qualified Zener diode family, engineered for voltage regulation in mission-critical analog circuits where parameter stability under extreme thermal, mechanical, and radiation stress is essential.
FAQ
What is the Zener voltage tolerance of the 1N748C-1/TR?
The 1N748C-1/TR has a nominal Zener voltage of 3.9 V with a guaranteed tolerance of ±2% at 30 mA test current (IZT), as defined by the "C" suffix in its nomenclature per Microsemi T4-LDS-0288. This tighter tolerance enables higher accuracy in feedback networks compared to the ±5% 1N748A-1/TR variant.
Is the 1N748C-1/TR RoHS compliant?
The 1N748C-1/TR is available in both RoHS-compliant (e3 suffix) and non-RoHS versions. Per Microsemi documentation, RoHS compliance applies only to commercial-grade units - JANTX-qualified 1N748C-1/TR devices use traditional tin-lead plating and are not RoHS compliant.
What does the "TR" suffix mean in 1N748C-1/TR?
The "TR" suffix indicates EIA-296 standard tape-and-reel packaging, enabling automated pick-and-place assembly. The 1N748C-1/TR is supplied in reels compatible with industry-standard feeders, with part marking retained on each unit per Microsemi mechanical specification.
What is the maximum power dissipation of the 1N748C-1/TR?
The 1N748C-1/TR is rated for 500 mW average power dissipation at a lead temperature (TL) of +50°C with 0.375 inch lead length from body. Power linearly derates to zero at +175°C, yielding ~400 mW usable power at +55°C ambient on a typical FR4 PCB.
Does the 1N748C-1/TR have radiation hardness certification?
Yes - the 1N748C-1/TR exhibits inherent radiation hardness as documented in Microsemi MicroNote 050. While not individually tested per MIL-STD-883, its metallurgically bonded DO-35 construction provides proven resilience to total ionizing dose (TID) and displacement damage in space and nuclear environments.
1N748C-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 3.9 V
- Tolerance:
- ±2%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N748C-1/TR FAQ
1.How can I place an order for 1N748C-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N748C-1/TR 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 1N748C-1/TR reliable?
The price and inventory of 1N748C-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N748C-1/TR is usually 5 days.
3.What payment methods are accepted for 1N748C-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N748C-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N748C-1/TR?
1N748C-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N748C-1/TR 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 1N748C-1/TR?
For technical support, including 1N748C-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N748C-1/TR requirements.
6.How does Aetrix verify that 1N748C-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N748C-1/TR 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 1N748C-1/TR meets industry standards.
7.What is the process for return or replacement of 1N748C-1/TR?
All 1N748C-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N748C-1/TR, 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 1N748C-1/TR part is unused and in its original packaging.
Return procedure for 1N748C-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N748C-1/TR Tags
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MM5Z5V1ST1G
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