My Inquiry
My Account
Diodes Incorporated 1N4739A-T
- Part No.:
- 1N4739A-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4739A-T.pdf
- Description:
- DIODE ZENER 9.1V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:7,818
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4739A-T from Diodes Incorporated is a 1.0 W, 9.1 V ±5% Zener diode in DO-41 glass package, designed for precision voltage regulation and reference applications with 5.0 Ω dynamic impedance at 28 mA test current and -65°C to +175°C operating temperature range. It delivers stable clamping in power supply feedback loops and overvoltage protection circuits.
For engineers reviewing the 1N4739A-T datasheet, 1N4739A-T pinout (cathode band polarity), 1N4739A-T application in voltage reference or shunt regulation, or 1N4739A-T equivalent for 9.1 V Zener replacement, this page provides verified electrical specs, thermal derating behavior, mechanical dimensions, and RoHS-compliant packaging details.
Technical Context
This discrete Zener diode operates in reverse breakdown mode with a nominal Zener voltage of 9.1 V at 28 mA (IZT), exhibiting a temperature coefficient of +0.035%/°C to +0.075%/°C - indicating positive drift with rising temperature. Its 5.0 Ω Zener impedance (ZZT) at IZT ensures low AC ripple sensitivity in reference paths.
Rated for 1.0 W dissipation at 25°C with 6.67 mW/°C linear derating above 50°C, it requires lead length control (9.5 mm from case) to maintain thermal resistance of 175 °C/W. Reverse leakage remains ≤10 µA at 7.0 V (VR), supporting low-power standby regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 9.1 V ±5% at 28 mA - defines precise DC reference point for feedback networks |
| Power Dissipation (Pd) | 1.0 W @ 25°C - supports continuous shunt regulation in low-to-medium current supplies |
| Zener Impedance (ZZT) | 5.0 Ω @ 28 mA - minimizes output voltage variation under dynamic load changes |
| Reverse Leakage (IR) | ≤10 µA @ 7.0 V - ensures negligible quiescent current in battery-powered references |
| Temperature Coefficient | +0.035 to +0.075 %/°C - enables predictable drift compensation in temperature-stable designs |
| Thermal Resistance (RθJA) | 175 °C/W - requires controlled PCB layout and lead length for safe thermal operation |
| Package | DO-41 glass - UL 94V-0 rated, Sn96.5Ag3.5 terminations, cathode band polarity marking |
Pinout & Package
DO-41 glass axial package with two terminals: anode (unmarked end) and cathode (band-marked end). Polarity is unambiguous; no internal circuitry or multi-pin configuration exists.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener reference ground node | Connected to lower potential side in shunt regulator; establishes reference return path |
| Cathode | Reverse breakdown terminal / regulated output node | Connected to input rail in shunt configuration; maintains 9.1 V relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| 1.0 W power rating | Enables robust voltage clamping in 5–100 mA load ranges without external heatsinking |
| ±5% VZ tolerance | Reduces binning requirements while maintaining accuracy for non-critical reference use |
| DO-41 glass construction | Provides hermetic sealing, high-temperature stability (-65°C to +175°C), and UL 94V-0 flammability rating |
| RoHS-compliant Sn96.5Ag3.5 finish | Ensures compatibility with lead-free reflow processes and meets EU Directive 2002/95/EC exemptions |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Used in TL431-based or discrete op-amp feedback networks to set output voltage in 12 V DC-DC converters. IC Role / Device Role / Timing Role: Zener reference element providing stable 9.1 V threshold for error amplifier comparison. Use Value: Maintains ±1.5% output regulation across line/load variations due to low ZZT and tight VZ tolerance. |
Use Scenario: Placed across motor driver outputs or microcontroller I/O lines to suppress transient spikes exceeding 10 V. IC Role / Device Role / Timing Role: Shunt clamping device diverting surge current away from sensitive inputs during ESD or inductive kick events. Use Value: Limits peak voltage to ≤9.8 V (VZ + IR×Rseries) with <100 ns response, protecting 3.3 V/5 V logic interfaces. |
| Low-Power Voltage Reference | Industrial Sensor Excitation |
Use Scenario: Supplies excitation voltage to resistive bridge sensors (e.g., strain gauges) in battery-operated condition monitoring nodes. IC Role / Device Role / Timing Role: Precision DC reference source replacing higher-cost IC references where 1% absolute accuracy suffices. Use Value: Draws only 28 mA typical, enabling >1-year operation on AA batteries while delivering stable 9.1 V ±0.46 V. |
Use Scenario: Provides regulated bias to RTD or thermistor signal conditioning circuits in HVAC control panels. IC Role / Device Role / Timing Role: Stable excitation source minimizing self-heating error and enabling ratiometric ADC measurements. Use Value: Temperature coefficient of +0.055%/°C average allows software compensation to achieve <0.1°C measurement uncertainty. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DFLZ9.1-7 | Surface-mount SOD-123FL package; 9.1 V ±5%; 500 mW rating; 10 Ω Zener impedance | Lower power handling and higher ZZT limit use to low-current references (<10 mA) | Select for space-constrained PCBs where thermal mass and lead length constraints preclude DO-41 |
| 1N4739A-A | Identical electrical specs and DO-41 package; differs only in 5K ammo pack vs. 5K tape-and-reel shipping format | No functional difference; identical performance in all circuit roles | Choose based solely on assembly line feeding method (pick-and-place vs. manual/hand-solder) |
Compared with DFLZ9.1-7, the 1N4739A-T offers 2× power margin and lower impedance for higher-current regulation; versus 1N4739A-A, it provides identical functionality with automated assembly compatibility via tape-and-reel delivery.
Availability
1N4739A-T is available at Aetrix Electronics and suitable for switch-mode power supply feedback, overvoltage protection clamp, and low-power voltage reference applications requiring stable component supply and long-term industrial availability.
Supply support for 1N4739A-T 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The 1N47xxA series belongs to Diodes' standard Zener diode product line, engineered for cost-effective, reliable voltage regulation in consumer, industrial, and computing power systems.
FAQ
What is the maximum allowable ambient temperature for continuous 1.0 W operation?
The 1N4739A-T sustains full 1.0 W dissipation only up to 50°C ambient. Above that, power must be linearly derated at 6.67 mW/°C - e.g., max 0.67 W at 100°C ambient. This assumes leads are held at 50°C with 9.5 mm length from case per datasheet Note 1.
How does the +0.035 to +0.075 %/°C temperature coefficient affect circuit accuracy?
Over a 100°C range (e.g., -25°C to +75°C), VZ shifts by +0.35% to +0.75%, or +32 mV to +68 mV from nominal 9.1 V. For precision references, this drift must be compensated via circuit topology or calibration - it is not inherently self-cancelling.
Can the 1N4739A-T replace a 1N4739A-A in the same PCB footprint?
Yes - both share identical DO-41 glass package dimensions, lead spacing, and electrical characteristics. The "-T" suffix denotes tape-and-reel packaging for automated placement; the "-A" suffix indicates ammo pack. No layout or schematic change is required.
Why is the 1N4739A-T marked "NOT RECOMMENDED FOR NEW DESIGN"?
Diodes Incorporated issued this notice because newer surface-mount Zeners (e.g., DFLZ9.1-7) offer improved manufacturability, smaller footprint, and better thermal performance in modern high-density assemblies - not due to reliability or specification shortcomings of the 1N4739A-T itself.
1N4739A-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 9.1 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
1N4739A-T FAQ
1.How can I place an order for 1N4739A-T through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4739A-T 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 1N4739A-T reliable?
The price and inventory of 1N4739A-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4739A-T is usually 5 days.
3.What payment methods are accepted for 1N4739A-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4739A-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4739A-T?
1N4739A-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4739A-T 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 1N4739A-T?
For technical support, including 1N4739A-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4739A-T requirements.
6.How does Aetrix verify that 1N4739A-T is sourced from the original manufacturer or authorized distributors?
All 1N4739A-T 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 1N4739A-T meets industry standards.
7.What is the process for return or replacement of 1N4739A-T?
All 1N4739A-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N4739A-T, 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 1N4739A-T part is unused and in its original packaging.
Return procedure for 1N4739A-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4739A-T 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
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…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
