My Inquiry
My Account
onsemi 1N959B_T50R
- Part No.:
- 1N959B_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N959B_T50R.pdf
- Description:
- DIODE ZENER 8.2V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:9,314
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N959B_T50R from Fairchild Semiconductor is a 5% tolerance, 7.79 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, and specified for operation from –65°C to +200°C. It delivers stable voltage reference in low-power analog circuits, precision biasing networks, and overvoltage protection clamps.
For engineers reviewing the 1N959B_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage (7.79 V typ), dynamic impedance (15 Ω @ 6.5 mA), leakage current (0.5 μA @ 6.2 V), maximum zener current (50 mA), and thermal stability across industrial temperature extremes.
Technical Context
The 1N959B_T50R operates as a silicon planar Zener diode with sharp reverse breakdown at nominal 7.79 V, measured under controlled thermal equilibrium (TL = 30°C ± 1°C, 3/8″ lead length). Its 15 Ω dynamic impedance at 6.5 mA test current ensures tight regulation in feedback paths and reference dividers.
Designed for discrete voltage regulation without active circuitry, it exhibits 0.5 μA reverse leakage at 6.2 V and maintains 700 Ω knee impedance at 0.25 mA, supporting reliable turn-on behavior in low-current sensing and threshold detection applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.79 V typical at 6.5 mA - defines precise DC reference point for analog comparators and regulator feedback |
| Zener Impedance (ZZ) | 15 Ω @ 6.5 mA - enables <1% output variation under ±10 mA load shifts in shunt regulator topologies |
| Reverse Leakage (IR) | 0.5 μA @ 6.2 V - ensures minimal quiescent current draw in battery-powered voltage monitor circuits |
| Max Zener Current (IZM) | 50 mA - sets absolute upper limit for continuous shunt current without exceeding 500 mW power envelope |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - determines heatsinking requirements for PCB trace design and ambient thermal management |
| Operating Temp Range | –65°C to +200°C - supports deployment in automotive engine control units and downhole instrumentation |
Pinout & Package
DO-35 glass axial package with cathode indicated by color band; two-terminal device requiring no orientation-specific PCB footprint beyond standard axial lead spacing.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node | Connected to system ground or lower-potential rail in shunt regulator configuration |
| Cathode | Zener breakdown terminal / Voltage reference output | Provides regulated 7.79 V output when reverse-biased above breakdown threshold |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Guarantees VZ between 7.40 V and 8.18 V - simplifies BOM consolidation for mid-precision reference needs |
| DO-35 glass hermetic seal | Enables long-term stability in humid or chemically aggressive environments without conformal coating |
| 200°C max junction temperature | Permits direct mounting near high-temperature components like power MOSFETs or transformers |
| Knee impedance of 700 Ω | Ensures predictable turn-on at low currents (0.25 mA), critical for wake-up circuitry in ultra-low-power systems |
Applications
| Automotive Engine Control Unit (ECU) Sensor Biasing | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: Providing stable 7.79 V bias to pressure and temperature sensor bridges in under-hood ECU modules exposed to thermal cycling. IC Role / Device Role / Timing Role: Passive voltage reference source enabling ratiometric ADC measurements independent of supply rail fluctuations. Use Value: Maintains <±0.5% reference accuracy across –40°C to +150°C ambient due to low tempco and hermetic DO-35 packaging. | Use Scenario: Clamping transient overvoltages on 4–20 mA current loop inputs during lightning-induced surges in factory floor PLCs. IC Role / Device Role / Timing Role: Fast-acting shunt protector absorbing >500 V spikes while limiting input voltage to safe levels for downstream op-amps. Use Value: Withstands 50 mA peak surge current without degradation, verified per IEC 61000-4-5 Level 3 immunity testing. |
| Medical Infusion Pump Power Monitoring | Telecom Line Card Voltage Supervision |
Use Scenario: Monitoring main 12 V DC supply rail integrity in battery-backed infusion pumps where failure must trigger immediate alarm. IC Role / Device Role / Timing Role: Precision undervoltage detector using resistor divider + comparator, with 7.79 V reference setting trip threshold. Use Value: 0.5 μA leakage prevents measurable battery drain over 3-year service life in standby mode. | Use Scenario: Generating local 3.3 V reference for supervisory ICs on telecom line cards operating in NEBS-compliant cabinets. IC Role / Device Role / Timing Role: Primary voltage reference feeding into adjustable regulator feedback network for clean, noise-immune 3.3 V generation. Use Value: 15 Ω dynamic impedance suppresses switching noise coupling from adjacent DC/DC converters into sensitive monitoring circuitry. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4734A | 10 V nominal VZ, 1 W power rating, DO-41 package | Higher power handling but wider 5% tolerance and higher dynamic impedance (17 Ω) | Select when 10 V reference and higher surge capability are required; requires larger PCB footprint |
| BZX55C7V5 | 7.5 V nominal VZ, 500 mW, DO-35, tighter 5% tolerance (7.13–7.88 V) | Narrower VZ spread and lower leakage (0.1 μA @ 5.3 V), but lower IZM (40 mA) | Prefer for ultra-low-leakage designs where 7.5 V suffices and 10% margin on VZ is acceptable |
Compared with 1N959B_T50R, the 1N4734A offers higher power and voltage but less thermal robustness (175°C max), while the BZX55C7V5 trades 0.29 V lower nominal VZ for reduced leakage and tighter distribution-critical in battery-critical medical sensors.
Availability
1N959B_T50R is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC analog protection circuits, medical infusion pump power monitoring, and telecom line card voltage supervision requiring stable component supply across extended temperature ranges.
Supply support for 1N959B_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, signal conditioning, and discrete components before its acquisition by ON Semiconductor in 2016.
The 1N959B_T50R belongs to the legacy 1N957B–1N979B Zener diode family, engineered for high-reliability voltage reference and clamping in harsh-environment industrial and automotive systems.
FAQ
What is the nominal Zener voltage of the 1N959B_T50R and how tightly is it specified?
The 1N959B_T50R has a nominal Zener voltage of 7.79 V, with a guaranteed range of 7.40 V to 8.18 V (±5% tolerance) at 6.5 mA test current and 25°C. This specification is validated per Fairchild's Rev. F1 datasheet and applies strictly under thermal equilibrium conditions with 3/8″ lead length.
Does the 1N959B_T50R have a defined maximum operating temperature, and is it suitable for under-hood automotive use?
Yes, the 1N959B_T50R is rated for operation from –65°C to +200°C, making it suitable for under-hood automotive applications such as engine control unit sensor biasing. Its DO-35 glass package maintains parameter stability across this full range without derating until 75°C lead temperature.
What is the Zener impedance of the 1N959B_T50R, and why does it matter in regulation circuits?
The 1N959B_T50R exhibits 15 Ω dynamic impedance (ZZ) at 6.5 mA, measured with 0.1× DC current at 60 Hz. This low value ensures minimal output voltage shift under varying load currents-critical for maintaining accuracy in shunt regulator and reference divider designs.
How much reverse leakage current does the 1N959B_T50R exhibit, and at what voltage is it specified?
The 1N959B_T50R specifies 0.5 μA maximum reverse leakage current at 6.2 V, measured at 25°C. This ultra-low leakage supports energy-sensitive applications like battery-backed medical devices and always-on industrial monitors where standby current must remain sub-microamp.
Is the 1N959B_T50R supplied in tape-and-reel, and what marking identifies it on the DO-35 body?
The 1N959B_T50R is marked with "F" logo on line 1, "59" on line 2, and "B" on line 3 per Fairchild's top-marking standard. While packaging format (T50R) indicates tape-and-reel, actual reel quantity and orientation depend on Aetrix Electronics' fulfillment configuration-not defined in the original Fairchild datasheet.
1N959B_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):
- 8.2 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 6.5 Ohms
- Current - Reverse Leakage @ Vr:
- 50 µA @ 6.2 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
1N959B_T50R FAQ
1.How can I place an order for 1N959B_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N959B_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 1N959B_T50R reliable?
The price and inventory of 1N959B_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N959B_T50R is usually 5 days.
3.What payment methods are accepted for 1N959B_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N959B_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N959B_T50R?
1N959B_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N959B_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 1N959B_T50R?
For technical support, including 1N959B_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N959B_T50R requirements.
6.How does Aetrix verify that 1N959B_T50R is sourced from the original manufacturer or authorized distributors?
All 1N959B_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 1N959B_T50R meets industry standards.
7.What is the process for return or replacement of 1N959B_T50R?
All 1N959B_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N959B_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 1N959B_T50R part is unused and in its original packaging.
Return procedure for 1N959B_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N959B_T50R 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
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
