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onsemi 1N5985B_T50A
- Part No.:
- 1N5985B_T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5985B_T50A.pdf
- Description:
- DIODE ZENER 2.4V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:5,808
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Product details
Overview
1N5985B_T50A from Fairchild Semiconductor is a 2.4 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, 100 Ω zener impedance at 5 mA test current, and 100 μA leakage current at 1 V reverse voltage. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning circuits.
For engineers reviewing the 1N5985B_T50A datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage (2.4 V), tolerance (±5%), thermal derating behavior, DO-35 mechanical compatibility, and low-leakage performance at VR = 1 V.
Technical Context
This device operates as a silicon planar Zener diode optimized for stable voltage regulation in low-current, low-power applications. Its 2.4 V breakdown is achieved via controlled doping and junction geometry, with specified thermal equilibrium measurement conditions (TL = 30°C ± 1°C, 3/8″ lead length).
The 1N5985B_T50A exhibits a typical zener impedance of 100 Ω at IZ = 5 mA and 1800 Ω at knee current IZK = 250 μA, indicating moderate dynamic resistance suitable for basic reference use but not ultra-low-noise precision systems. Maximum Zener current IZM is 208 mA under worst-case voltage and derating conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 2.4 V min / 2.52 V max at IZ = 5 mA - defines usable regulation band for 2.4 V reference design |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - sets maximum steady-state thermal load on PCB with 3/8″ leads |
| Zener Impedance (ZZ) | 100 Ω @ IZ = 5 mA - determines output voltage variation under small-signal load changes |
| Leakage Current (IR) | 100 μA @ VR = 1 V - limits error current in high-impedance bias networks |
| Operating Temp Range | –65°C to +200°C - supports industrial and automotive under-hood environments |
| Forward Voltage (VF) | 1.2 V max @ IF = 200 mA - ensures predictable forward conduction during polarity-reversal protection |
Pinout & Package
DO-35 glass axial package with cathode indicated by color band; two-terminal device with no internal connections beyond anode and cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal in forward bias; connected to lower potential in Zener operation | Reference ground node connection point when used as shunt regulator |
| Cathode | Negative terminal in forward bias; connected to higher potential in Zener operation | Voltage reference output node; marked by color band on DO-35 body |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables consistent 2.4 V reference across production lots without post-assembly trimming |
| DO-35 glass package | Provides hermetic sealing and thermal stability for long-term parameter retention |
| 100 μA leakage at 1 V | Minimizes loading error in high-resistance voltage divider or sensor bias networks |
| 208 mA max Zener current | Supports robust transient clamping in low-energy surge events with appropriate series resistance |
Applications
| Industrial Sensor Signal Conditioning | Low-Power Microcontroller Reset Circuit |
|---|---|
Use Scenario: Stabilizing reference voltage for 12-bit ADC inputs in temperature transmitters operating from 3.3 V rails. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 2.4 V bias to op-amp input stage. Use Value: Maintains <±0.5 LSB error over –40°C to +85°C due to tight 2.4 V tolerance and low tempco inherent to 2.4 V Zeners. |
Use Scenario: Generating a clean reset threshold for ARM Cortex-M0+ MCUs powered from unregulated 3.0–3.6 V supplies. IC Role / Device Role / Timing Role: Zener-based voltage monitor feeding comparator input to assert reset below 2.3 V. Use Value: Delivers deterministic reset activation at 2.4 V ±5%, eliminating need for dedicated reset IC in cost-sensitive designs. |
| Automotive Cabin Control Panel | Consumer Audio Bias Network |
Use Scenario: Clamping ESD transients on LIN bus interface lines exposed to ISO 10605 pulses. IC Role / Device Role / Timing Role: Low-capacitance transient voltage suppressor placed across LIN line and ground. Use Value: Absorbs 208 mA peak pulse current without degradation, leveraging DO-35's robust thermal mass. |
Use Scenario: Setting bias point for Class-AB headphone amplifier input stage in battery-powered portable speakers. IC Role / Device Role / Timing Role: Precision DC reference source for dual-supply op-amp common-mode level shift. Use Value: Provides 2.4 V reference with <100 μA leakage, preventing audible pop/click during power-up sequencing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4730A | 3.9 V nominal, same DO-35 package, 1 W rating, 9 Ω ZZ @ 20 mA | Higher voltage, higher power, lower impedance - unsuitable for 2.4 V reference but better for 3.9 V clamping | Select only if system requires 3.9 V regulation and can accommodate higher power dissipation |
| BZX55C2V4 | 2.4 V nominal, ±5% tolerance, DO-35, 500 mW, 100 Ω ZZ @ 5 mA - identical electrical specs | Same regulation voltage and package; manufactured by ON Semiconductor with alternate marking and traceability | Drop-in replacement with identical performance; verify sourcing channel compliance for automotive qualification |
Compared with 1N4730A and BZX55C2V4, the 1N5985B_T50A offers optimal fit for 2.4 V low-power reference needs where strict voltage matching and DO-35 footprint are mandatory, while BZX55C2V4 provides direct functional equivalence and 1N4730A serves distinct higher-voltage use cases.
Availability
1N5985B_T50A is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, low-power microcontroller reset circuits, and automotive cabin control panels requiring stable component supply and long-lifecycle support.
Supply support for 1N5985B_T50A 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; legacy products maintain full specification compliance and industrial qualification.
The 1N5985B_T50A belongs to Fairchild's 1N59xxB Zener diode family designed for general-purpose voltage regulation and transient suppression in cost-sensitive, space-constrained applications using standard DO-35 assembly processes.
FAQ
What is the exact Zener voltage range for 1N5985B_T50A at 5 mA test current?
The 1N5985B_T50A has a guaranteed Zener voltage range of 2.4 V minimum to 2.52 V maximum at IZ = 5 mA and TA = 25°C, reflecting its ±5% tolerance specification. This range is measured under thermal equilibrium conditions with lead temperature held at 30°C ± 1°C and 3/8″ lead length, ensuring repeatability across production lots.
Can 1N5985B_T50A be used in surface-mount designs?
No - the 1N5985B_T50A uses a DO-35 glass axial package with radial leads, requiring through-hole mounting. It is not compatible with SMT reflow or wave soldering processes. For surface-mount equivalents, consider SOD-123 or SOD-323 packaged Zeners such as BZT52-B2V4, which differ in thermal performance and mechanical reliability.
What is the maximum allowable Zener current for 1N5985B_T50A at 25°C ambient?
At TA = 25°C, the 1N5985B_T50A supports up to 208 mA maximum Zener current (IZM), calculated from its 500 mW power rating and nominal 2.4 V Zener voltage. This value assumes ideal heat sinking; actual usable current must be reduced per the 4.0 mW/°C derating curve when lead temperature exceeds 75°C.
How does the 1N5985B_T50A leakage current compare to higher-voltage Zeners in the same family?
The 1N5985B_T50A specifies 100 μA leakage current at VR = 1 V, which is higher than later devices in the series (e.g., 1N5994B: 2 μA at VR = 3 V). This reflects the physics of low-voltage Zener breakdown, where tunneling dominates and increases reverse leakage - a known trade-off for 2.4 V regulation capability.
Is the 1N5985B_T50A RoHS compliant and halogen-free?
Yes - the 1N5985B_T50A meets RoHS Directive 2011/65/EU requirements and is halogen-free per JEDEC JS709A. Fairchild's Rev. C2 datasheet (March 2010) confirms compliance for this part number, with material declarations available through authorized distributors' product change notifications.
1N5985B_T50A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 100 Ohms
- Current - Reverse Leakage @ Vr:
- 100 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
1N5985B_T50A FAQ
1.How can I place an order for 1N5985B_T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5985B_T50A 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 1N5985B_T50A reliable?
The price and inventory of 1N5985B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5985B_T50A is usually 5 days.
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4.How is shipping managed for 1N5985B_T50A?
1N5985B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5985B_T50A 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 1N5985B_T50A?
For technical support, including 1N5985B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5985B_T50A requirements.
6.How does Aetrix verify that 1N5985B_T50A is sourced from the original manufacturer or authorized distributors?
All 1N5985B_T50A 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 1N5985B_T50A meets industry standards.
7.What is the process for return or replacement of 1N5985B_T50A?
All 1N5985B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5985B_T50A, 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 1N5985B_T50A part is unused and in its original packaging.
Return procedure for 1N5985B_T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5985B_T50A Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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