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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

onsemi 1N4371A_T50R

Name: 1N4371A_T50R
Brand: onsemi
SKU: 1N4371A_T50R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N4371A_T50R

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: 1N4371A_T50R.pdf

Description:: DIODE ZENER 2.7V 500MW DO35

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Product details

Overview

1N4371A_T50R from Fairchild Semiconductor is a 2.7 V ±5% silicon Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C, with 30 Ω dynamic impedance at 20 mA and 75 µA maximum reverse leakage at 125°C, used for precision voltage reference and overvoltage protection in low-power analog circuits.

For engineers reviewing the 1N4371A_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior, junction temperature range, and cathode-band polarity marking compliance per MIL-STD-750.

Technical Context

This device operates in reverse breakdown mode with a nominal zener voltage of 2.7 V at 20 mA test current, exhibiting a typical dynamic impedance of 30 Ω and maximum reverse leakage of 75 µA at 125°C ambient. Its DO-35 glass package supports lead temperature-controlled testing per MIL-STD-750 Method 2054.

The 1N4371A_T50R follows the 1N4370A–1N4372A family design, sharing identical absolute maximum ratings (500 mW, -65°C to +200°C), 5% voltage tolerance, and cathode band polarity marking. It is not rated for surge current or transient voltage suppression beyond steady-state zener operation.

Key Specifications

Parameter	Value and Actual Design Meaning
V_Z @ I_Z = 20 mA	2.7 V typical; defines stable reference voltage under standard test conditions
Zener Tolerance	±5%; ensures voltage accuracy within 2.57–2.84 V across production lot
Z_Z @ I_Z = 20 mA	30 Ω max; limits output impedance impact on regulation stability
P_D @ T_L ≤ 75°C	500 mW; sets maximum continuous power handling with 3/8″ lead length
T_J/T_STG	-65°C to +200°C; enables operation in extended industrial and automotive under-hood environments
I_R @ V_R = 1 V	100 µA max at 25°C; quantifies off-state leakage affecting high-impedance bias networks
Forward Voltage	1.5 V max @ I_F = 200 mA; defines forward conduction threshold for dual-polarity protection use

Pinout & Package

DO-35 glass axial package with cathode indicated by a single color band; leads are tinned copper alloy, 0.46 mm diameter, 3/8″ length standard for thermal testing.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener breakdown return path	Connected to lower potential node in shunt regulator or clamp configuration
Cathode	Zener breakdown terminal / Reference output node	Marked with color band; supplies regulated voltage when reverse-biased

Key Features

Feature	Design Value
Stable 2.7 V reference	Guaranteed 2.57–2.84 V range supports ±5% analog supply tolerance budgets
Low dynamic impedance	30 Ω max ensures <1% output variation across 5–25 mA load current changes
High-temperature operation	Rated to +200°C junction enables use in sealed enclosures without forced cooling
DO-35 glass reliability	Hermetic seal meets MIL-STD-750 Method 1001 for moisture resistance and long-term stability

Applications

Low-Voltage Reference	Overvoltage Clamp
Use Scenario: Providing stable 2.7 V bias for op-amp input stages in battery-powered sensor signal conditioning. IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise DC operating point for analog front-end circuitry. Use Value: Maintains amplifier offset stability across -40°C to +85°C ambient due to tight 5% tolerance and low tempco inherent to 2.7 V Zeners.	Use Scenario: Protecting microcontroller I/O pins against ESD-induced transients exceeding 3.3 V rail. IC Role / Device Role / Timing Role: Passive clamping element diverting excess energy to ground before IC damage occurs. Use Value: Limits pin voltage to ≤2.84 V during fault, well below 3.6 V absolute maximum rating of most 3.3 V logic inputs.
Power Supply Monitor	Current Source Bias
Use Scenario: Detecting brown-out condition in 3.0 V system by comparing regulated 2.7 V reference against scaled supply voltage. IC Role / Device Role / Timing Role: Precision voltage threshold generator feeding comparator input. Use Value: Enables detection of supply drop to 2.85 V (95% of nominal) with minimal hysteresis due to low Z_Z.	Use Scenario: Setting constant current through LED driver transistor base in discrete constant-current source. IC Role / Device Role / Timing Role: Voltage-defined current-setting element in emitter-degenerated BJT bias network. Use Value: Delivers 2.7 V reference to establish 270 µA base current with 10 kΩ resistor, independent of supply variation above 3.0 V.

Low-Voltage Reference

Overvoltage Clamp

Use Scenario: Providing stable 2.7 V bias for op-amp input stages in battery-powered sensor signal conditioning.

IC Role / Device Role / Timing Role: Shunt voltage reference establishing precise DC operating point for analog front-end circuitry.

Use Value: Maintains amplifier offset stability across -40°C to +85°C ambient due to tight 5% tolerance and low tempco inherent to 2.7 V Zeners.

Use Scenario: Protecting microcontroller I/O pins against ESD-induced transients exceeding 3.3 V rail.

IC Role / Device Role / Timing Role: Passive clamping element diverting excess energy to ground before IC damage occurs.

Use Value: Limits pin voltage to ≤2.84 V during fault, well below 3.6 V absolute maximum rating of most 3.3 V logic inputs.

Power Supply Monitor

Current Source Bias

Use Scenario: Detecting brown-out condition in 3.0 V system by comparing regulated 2.7 V reference against scaled supply voltage.

IC Role / Device Role / Timing Role: Precision voltage threshold generator feeding comparator input.

Use Value: Enables detection of supply drop to 2.85 V (95% of nominal) with minimal hysteresis due to low Z_Z.

Use Scenario: Setting constant current through LED driver transistor base in discrete constant-current source.

IC Role / Device Role / Timing Role: Voltage-defined current-setting element in emitter-degenerated BJT bias network.

Use Value: Delivers 2.7 V reference to establish 270 µA base current with 10 kΩ resistor, independent of supply variation above 3.0 V.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener reference applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4728A	3.3 V nominal, same DO-35 package, 5% tolerance, 100 mW higher P_D (1 W)	Higher voltage reference; unsuitable where 2.7 V is required for headroom or compatibility	Select only if circuit requires ≥3.14 V reference and can accommodate higher power dissipation
BZX55C2V7	2.7 V nominal, DO-35, 5% tolerance, but rated for 500 mW at T_A = 25°C (not lead-temp controlled)	Thermal derating defined at ambient vs. lead temperature; less predictable in high-T_L PCB layouts	Prefer 1N4371A_T50R where lead temperature control or MIL-STD-750 compliance is required

Compared with 1N4371A_T50R, the 1N4728A provides higher reference voltage and power handling but cannot substitute directly in 2.7 V designs, while the BZX55C2V7 offers identical voltage rating but lacks lead-temperature-based derating specification critical for thermally constrained layouts.

Availability

1N4371A_T50R is available at Aetrix Electronics and suitable for low-power voltage reference, overvoltage clamping, and analog biasing applications requiring stable component supply across industrial control, sensor interface, and legacy embedded systems.

Supply support for 1N4371A_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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The 1N4371A_T50R belongs to Fairchild's legacy 1N437x series Zener diodes, designed for general-purpose precision voltage regulation in cost-sensitive, low-to-medium volume industrial and consumer electronics.

FAQ

What is the exact zener voltage range for 1N4371A_T50R at 20 mA?

The 1N4371A_T50R has a guaranteed zener voltage range of 2.57 V to 2.84 V at I_Z = 20 mA and T_A = 25°C, reflecting its ±5% tolerance. This range is verified per Fairchild's Rev. D1 datasheet and applies to all units marked "37" and "1A" on second and third lines respectively. The 1N4371A_T50R maintains this specification across its qualified temperature range when operated within absolute maximum ratings.

Does 1N4371A_T50R support operation above 125°C junction temperature?

No - the 1N4371A_T50R is rated for junction and storage temperatures from -65°C to +200°C, but its electrical characteristics (including V_Z, Z_Z, and I_R) are specified only up to +125°C. Operation above 125°C requires validation of parameter drift and reliability; the 1N4371A_T50R datasheet does not provide characterization data beyond that point. For 1N4371A_T50R, thermal design must ensure T_J ≤ 125°C during normal operation.

How is the cathode identified on 1N4371A_T50R?

The cathode of the 1N4371A_T50R is marked by a single color band on the DO-35 glass body, consistent with industry-standard polarity marking. Per Fairchild's top-marking specification, the device displays "F" logo on line 1, "37" on line 2, and "1A" on line 3 - confirming it as part of the 1N437x family. This cathode band must be oriented toward the higher potential node in shunt regulator configurations. The 1N4371A_T50R follows MIL-STD-750 polarity conventions.

Can 1N4371A_T50R replace 1N4370A or 1N4372A in existing designs?

Yes - the 1N4371A_T50R shares identical package (DO-35), absolute maximum ratings (500 mW, -65°C to +200°C), and test methodology with 1N4370A and 1N4372A, differing only in nominal zener voltage (2.7 V vs. 2.4 V and 3.0 V). No PCB or schematic changes are needed for substitution, provided the target reference voltage matches 2.7 V. All three devices use the same marking format and thermal derating curve. The 1N4371A_T50R is fully compatible within this family.

What is the forward voltage specification for 1N4371A_T50R?

The forward voltage of the 1N4371A_T50R is specified as ≤1.5 V at I_F = 200 mA, per Fairchild's Rev. D1 datasheet. This value characterizes anode-to-cathode conduction under high forward current and is relevant when the device is used bidirectionally - for example, in symmetrical transient clamping or dual-rail protection schemes. The 1N4371A_T50R exhibits standard silicon diode forward behavior outside its zener breakdown region.

1N4371A_T50R Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: DO-204AH, DO-35, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 2.7 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 30 Ohms

Current - Reverse Leakage @ Vr:: 75 µA @ 1 V

Voltage - Forward (Vf) (Max) @ If:: 1.5 V @ 200 mA

Operating Temperature:: -65°C ~ 200°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-35

1N4371A_T50R FAQ

1.How can I place an order for 1N4371A_T50R through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N4371A_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 1N4371A_T50R reliable?

The price and inventory of 1N4371A_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4371A_T50R is usually 5 days.

3.What payment methods are accepted for 1N4371A_T50R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4371A_T50R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N4371A_T50R?

1N4371A_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N4371A_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 1N4371A_T50R?

For technical support, including 1N4371A_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4371A_T50R requirements.

6.How does Aetrix verify that 1N4371A_T50R is sourced from the original manufacturer or authorized distributors?

All 1N4371A_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 1N4371A_T50R meets industry standards.

7.What is the process for return or replacement of 1N4371A_T50R?

All 1N4371A_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N4371A_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 1N4371A_T50R part is unused and in its original packaging.

Return procedure for 1N4371A_T50R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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