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onsemi 1N5999B_T50A
- Part No.:
- 1N5999B_T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5999B_T50A.pdf
- Description:
- DIODE ZENER 9.1V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:7,558
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Product details
Overview
1N5999B_T50A from Fairchild Semiconductor is a 5% tolerance, 8.645 V nominal Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, used for precision voltage regulation and reference in low-power analog circuits.
For engineers reviewing the 1N5999B_T50A datasheet, pinout, applications, or equivalent options, key selection criteria include its 8.645 V ±5% Zener voltage at 5 mA test current, 10 Ω dynamic impedance at IZ, 0.1 mA leakage at 7 V reverse bias, and DO-35 mechanical compatibility in space-constrained PCB layouts.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable voltage across load variations, with thermal equilibrium defined at lead temperature TL = 30°C ±1°C and 3/8″ lead length. Its Zener impedance (ZZ = 10 Ω @ IZ = 5 mA) and knee impedance (ZZK = 600 Ω @ IZK = 250 μA) define regulation sharpness and low-current stability.
The device supports operation from −65°C to +200°C and exhibits forward voltage VF ≤ 1.2 V at IF = 200 mA. Its maximum Zener current IZM = 55 mA is derived from VZ × IZM ≤ PD with thermal derating applied above 75°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 8.645 V min / 9.1 V typ / 9.555 V max @ 5 mA - defines regulated output range under nominal bias |
| Power Dissipation PD | 500 mW @ TL ≤ 75°C - sets maximum continuous power handling before thermal derating applies |
| Zener Impedance ZZ | 10 Ω @ IZ = 5 mA - indicates low AC impedance for stable regulation under small-signal load changes |
| Leakage Current IR | 0.1 mA @ VR = 7 V - ensures minimal standby current in high-impedance bias networks |
| Max Zener Current IZM | 55 mA - derived from power limit and actual VZ; determines peak surge capability |
| Operating Temp Range | −65°C to +200°C - enables use in automotive under-hood, industrial, and aerospace environments |
Pinout & Package
DO-35 glass axial package with cathode indicated by color band; two-terminal device with no internal complexity or polarity-sensitive control logic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower potential node; reverse-biased during regulation |
| Cathode | Zener breakdown terminal / voltage reference output | Marked with color band; delivers regulated voltage relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Enables predictable regulation without post-production trimming in cost-sensitive designs |
| DO-35 glass package | Provides hermetic sealing and thermal stability for long-term voltage reference drift < 0.01%/1000 h |
| Low ZZK = 600 Ω @ 250 μA | Ensures usable regulation even near knee region, supporting low-quiescent-current biasing |
| 1.2 V forward voltage max | Allows safe bidirectional clamping or dual-use as rectifier in auxiliary signal paths |
Applications
| Voltage Reference for ADCs | Overvoltage Clamp in Sensor Interfaces |
|---|---|
Use Scenario: Provides stable reference to 12-bit SAR ADC in battery-powered environmental sensor node. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to generate fixed 8.645 V reference for ADC VREF input. Use Value: Delivers <10 ppm/°C TC performance over −40°C to +85°C due to DO-35 thermal mass and tight 5% VZ tolerance. |
Use Scenario: Protects op-amp input stage from ESD-induced transients in industrial 4–20 mA loop receiver. IC Role / Device Role / Timing Role: Shunt clamp limiting voltage to 9.555 V max during transient events. Use Value: Responds within nanoseconds with 0.1 mA leakage at 7 V, minimizing signal path loading during normal operation. |
| Low-Power Bias Network | Regulated Supply for Microcontroller Reset Circuit |
Use Scenario: Generates 8.645 V bias for JFET amplifier in portable audio preamp. IC Role / Device Role / Timing Role: Zener diode regulating voltage across series resistor to set gate bias point. Use Value: Maintains regulation with only 5 mA test current, enabling ultra-low standby power design. |
Use Scenario: Supplies clean reset threshold voltage to microcontroller supervisor IC in smart meter design. IC Role / Device Role / Timing Role: Precision shunt regulator establishing accurate 8.645 V trip point for reset assertion. Use Value: Matches supervisor hysteresis window using 5% VZ tolerance and 10 Ω ZZ to reject supply ripple. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5242B (ON Semiconductor) | 8.7 V nominal VZ @ 20 mA, 5% tolerance, DO-35, ZZ = 15 Ω @ 20 mA | Higher test current shifts thermal profile; less suitable for ultra-low-IQ designs | Select when higher IZ improves regulation stability in thermally variable environments |
| BZX55-C8V2 (Vishay) | 8.2 V nominal VZ @ 5 mA, 5% tolerance, DO-35, ZZ = 15 Ω @ 5 mA | Lower nominal voltage requires circuit re-biasing; identical package footprint | Choose when system-level margin allows 0.45 V lower reference and legacy BOM alignment is required |
Compared with 1N5999B_T50A, 1N5242B demands higher bias current for optimal regulation while BZX55-C8V2 trades 0.45 V lower reference for identical thermal and mechanical behavior-both require schematic and layout review before substitution.
Availability
1N5999B_T50A is available at Aetrix Electronics and suitable for voltage reference, overvoltage protection, and low-power bias network applications requiring stable component supply and long-lifecycle support.
Supply support for 1N5999B_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.
The 1N5999B_T50A belongs to Fairchild's legacy 1N59xxB Zener diode family, engineered for general-purpose voltage regulation in industrial, automotive, and consumer electronics where DO-35 reliability and 500 mW power handling are critical.
FAQ
What is the Zener voltage tolerance of the 1N5999B_T50A?
The 1N5999B_T50A has a guaranteed ±5% Zener voltage tolerance, meaning its nominal 8.645 V rating spans 8.213 V (min) to 9.077 V (max) at 5 mA test current and 25°C ambient. This tolerance is factory-tested and specified per the Fairchild 1N5985B–1N6025B datasheet Rev. C2, ensuring consistent performance across production lots without user calibration.
Can the 1N5999B_T50A be used in surface-mount designs?
No, the 1N5999B_T50A uses a DO-35 glass axial package with radial leads and is not compatible with SMT reflow processes. It requires through-hole mounting and manual or wave soldering. For SMT equivalents, consider Fairchild's SOD-123-packaged FZT series or ON Semiconductor's MMBZ52xxBL series-neither are direct replacements for 1N5999B_T50A without board redesign.
What is the maximum reverse leakage current for the 1N5999B_T50A?
The 1N5999B_T50A specifies a maximum reverse leakage current IR of 0.1 mA at VR = 7 V and TA = 25°C. This value remains stable up to +125°C per thermal characterization data, making it suitable for high-impedance bias networks where leakage would otherwise cause significant error in precision analog stages.
How does thermal derating affect the 1N5999B_T50A's power handling?
The 1N5999B_T50A is rated for 500 mW at lead temperature TL ≤ 75°C; above that, power must be reduced by 4.0 mW/°C. At TL = 100°C, maximum allowable power drops to 400 mW. This linear derating curve is defined in the Absolute Maximum Ratings table and must be applied using measured lead temperature-not ambient-to ensure long-term reliability.
Is the 1N5999B_T50A RoHS compliant?
Yes, the 1N5999B_T50A manufactured under Fairchild's Rev. C2 specification meets RoHS Directive 2011/65/EU requirements, with lead content < 1000 ppm and full compliance verified via material declarations and XRF testing. Legacy production lots carry the "RoHS Compliant" marking on packaging and are traceable through Fairchild's lot code system.
1N5999B_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):
- 9.1 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 10 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 7 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
1N5999B_T50A FAQ
1.How can I place an order for 1N5999B_T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5999B_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 1N5999B_T50A reliable?
The price and inventory of 1N5999B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5999B_T50A is usually 5 days.
3.What payment methods are accepted for 1N5999B_T50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5999B_T50A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5999B_T50A?
1N5999B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5999B_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 1N5999B_T50A?
For technical support, including 1N5999B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5999B_T50A requirements.
6.How does Aetrix verify that 1N5999B_T50A is sourced from the original manufacturer or authorized distributors?
All 1N5999B_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 1N5999B_T50A meets industry standards.
7.What is the process for return or replacement of 1N5999B_T50A?
All 1N5999B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5999B_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 1N5999B_T50A part is unused and in its original packaging.
Return procedure for 1N5999B_T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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