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onsemi 1N4742A_T50R
- Part No.:
- 1N4742A_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4742A_T50R.pdf
- Description:
- DIODE ZENER 12V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:4,256
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Product details
Overview
1N4742A_T50R from ON Semiconductor is a 12 V, ±5% tolerance, 1 W axial-leaded Zener diode in DO-41 glass package, rated for 9.1 V minimum reverse breakdown at 0.25 µA leakage and 21 Ω dynamic impedance at 21 mA test current, used for precision voltage regulation in power supply feedback paths and reference circuits.
For engineers reviewing the 1N4742A_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5%), thermal derating (6.67 mW/°C above 50°C), junction temperature range (–65°C to +200°C), and DO-41 mechanical compatibility with through-hole PCB layouts.
Technical Context
This device operates as a two-terminal voltage reference by exploiting controlled reverse-biased avalanche breakdown. Its 12 V nominal Zener voltage is specified at 21 mA test current (IZ), with typical dynamic impedance of 21 Ω and maximum 21 Ω at IZ - ensuring stable regulation under moderate load transients.
The 1N4742A_T50R exhibits low leakage (≤0.25 µA at VR = 9.1 V) and supports non-repetitive peak reverse surge currents up to 380 mA (8.3 ms square wave), making it suitable for transient-suppressed DC rail stabilization in industrial and automotive auxiliary supplies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 12 V nominal, min 11.4 V / max 12.6 V at IZ = 21 mA - defines regulated output voltage tolerance band |
| Power Dissipation (PD) | 1.0 W @ TL ≤ 50°C, lead length 3/8″ - sets maximum continuous DC power handling |
| Zener Impedance (ZZ) | 21 Ω max at IZ = 21 mA - determines regulation stiffness under load variation |
| Leakage Current (IR) | ≤0.25 µA at VR = 9.1 V - ensures minimal error current in high-impedance reference nodes |
| Operating Temperature | –65°C to +200°C - enables use in extended-environment industrial and under-hood automotive applications |
| Thermal Derating | 6.67 mW/°C above 50°C - defines safe power reduction slope for elevated ambient conditions |
| Surge Current (IZSM) | 380 mA (8.3 ms, non-repetitive) - supports brief overvoltage events without failure |
Pinout & Package
DO-41 glass axial package with cathode indicated by a single color band. Leads are tinned copper-clad steel; body diameter 2.0–2.7 mm, length 4.5–7.0 mm, lead diameter 0.4–0.6 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to circuit ground or lower potential rail in shunt regulator configuration |
| Cathode | Zener breakdown terminal / regulated output node | Connected to input via series resistor and to load; maintains ~12 V relative to anode when reverse-biased |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables predictable regulation without post-manufacture trimming in cost-sensitive designs |
| 1 W power rating with DO-41 footprint | Provides higher power headroom than 0.5 W Zeners while maintaining legacy through-hole compatibility |
| Low 21 Ω dynamic impedance | Minimizes output voltage shift across 5–25 mA operating range in feedback loops |
| –65°C to +200°C operating range | Supports deployment in engine control units, motor drives, and outdoor power electronics |
| Cathode band polarity marking | Ensures unambiguous orientation during manual or automated assembly |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Stabilizing output voltage in isolated flyback converters via optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 12 V threshold to TL431 or optocoupler LED drive circuit. Use Value: Tight ±5% VZ tolerance and low ZZ ensure <±1% output regulation accuracy across line/load/temperature. |
Use Scenario: Generating stable excitation voltage for resistive bridge sensors in factory automation systems. IC Role / Device Role / Timing Role: Low-drift, low-noise DC reference source powering Wheatstone bridges or RTD interfaces. Use Value: Sub-microamp leakage and 21 Ω impedance minimize sensor offset drift and improve measurement resolution. |
| Automotive Body Control Module | Legacy Microcontroller Reset Circuit |
Use Scenario: Regulating 12 V battery-derived rail to 5 V or 3.3 V logic supply in BCM sub-regulators. IC Role / Device Role / Timing Role: Primary shunt clamp protecting downstream LDOs from overvoltage during load dump transients. Use Value: 380 mA surge rating and –65°C to +200°C range meet ISO 7637-2 pulse 5a/b requirements and under-hood thermal limits. |
Use Scenario: Providing clean reset threshold for 8-bit MCUs in industrial controllers where external reset ICs are omitted. IC Role / Device Role / Timing Role: Precision voltage detector triggering POR or brown-out reset at defined 12 V system rail level. Use Value: Guaranteed 11.4–12.6 V breakdown window ensures deterministic reset assertion across temperature and aging. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A (ON Semi) | Same electrical specs and DO-41 package; T50R suffix denotes tape-and-reel packaging - no functional difference | No change in circuit design or layout required; differs only in packaging format (reel vs. bulk) | Select 1N4742A_T50R for automated SMT placement; choose bulk 1N4742A for hand-solder prototyping |
| BZX55C12 (Vishay) | Same 12 V ±5%, 1 W, DO-41; slightly higher ZZ (25 Ω max) and wider leakage spec (≤1 µA at 9.1 V) | Acceptable in less demanding regulation tasks but may degrade feedback accuracy in precision SMPS | Prefer 1N4742A_T50R where low impedance and tight leakage are critical; BZX55C12 suits cost-optimized consumer-grade supplies |
Compared with 1N4742A (bulk) and BZX55C12, the 1N4742A_T50R delivers identical regulation performance with optimized logistics for high-volume assembly, while offering superior impedance and leakage control versus the Vishay alternative in precision feedback paths.
Availability
1N4742A_T50R is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor interfaces, and automotive body control modules requiring stable component supply and long-term manufacturability.
Supply support for 1N4742A_T50R 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The 1N47xxA series was designed as a standardized, high-reliability Zener reference family for general-purpose voltage regulation - balancing precision, ruggedness, and cost across broad industrial and automotive applications.
FAQ
What is the Zener voltage tolerance of the 1N4742A_T50R?
The 1N4742A_T50R has a nominal Zener voltage of 12 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 11.4 V and 12.6 V when measured at 21 mA test current and 25°C. This tolerance is guaranteed per ON Semiconductor's 1N4728A–1N4758A datasheet Rev. 8, and applies directly to the 1N4742A_T50R as a tape-and-reel variant of the base 1N4742A device.
Can the 1N4742A_T50R be used in place of the bulk 1N4742A?
Yes - the 1N4742A_T50R is functionally identical to the bulk 1N4742A, differing only in packaging format (tape-and-reel vs. loose parts). All electrical specifications, thermal ratings, and mechanical dimensions are identical. The "T50R" suffix indicates 500-unit tape-and-reel packaging optimized for automated pick-and-place assembly, with no impact on circuit performance or reliability of the 1N4742A_T50R itself.
What is the maximum non-repetitive peak reverse current for the 1N4742A_T50R?
The 1N4742A_T50R supports a non-repetitive peak reverse surge current (IZSM) of 380 mA for an 8.3 ms square wave pulse, as specified in the ON Semiconductor 1N4728A–1N4758A datasheet. This rating enables the 1N4742A_T50R to withstand common power-line transients and load-dump events without degradation, provided the average power remains within its 1 W DC limit.
Does the 1N4742A_T50R have a specified Zener impedance at low test currents?
Yes - the 1N4742A_T50R specifies Zener impedance (ZZK) of 7 Ω maximum at IZK = 9 mA, which reflects its dynamic resistance near knee voltage. This value, alongside the 21 Ω max at 21 mA, confirms stable regulation behavior across its operational current range and supports use in low-current reference applications where knee-region performance matters.
Is the 1N4742A_T50R suitable for automotive under-hood applications?
Yes - the 1N4742A_T50R is rated for an operating junction temperature range of –65°C to +200°C and features a DO-41 glass package qualified for high-reliability environments. Its 380 mA surge rating and robust leakage performance (≤0.25 µA at 9.1 V) align with requirements for engine control, lighting, and body electronics, making the 1N4742A_T50R appropriate for under-hood deployment when thermally managed per datasheet derating rules.
1N4742A_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 12 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 9 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 9.1 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
1N4742A_T50R FAQ
1.How can I place an order for 1N4742A_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4742A_T50R 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 1N4742A_T50R reliable?
The price and inventory of 1N4742A_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4742A_T50R is usually 5 days.
3.What payment methods are accepted for 1N4742A_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4742A_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4742A_T50R?
1N4742A_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4742A_T50R 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 1N4742A_T50R?
For technical support, including 1N4742A_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4742A_T50R requirements.
6.How does Aetrix verify that 1N4742A_T50R is sourced from the original manufacturer or authorized distributors?
All 1N4742A_T50R 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 1N4742A_T50R meets industry standards.
7.What is the process for return or replacement of 1N4742A_T50R?
All 1N4742A_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N4742A_T50R, 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 1N4742A_T50R part is unused and in its original packaging.
Return procedure for 1N4742A_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4742A_T50R Tags
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