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onsemi 1N970B_T50A
- Part No.:
- 1N970B_T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N970B_T50A.pdf
- Description:
- DIODE ZENER 24V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:6,737
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Product details
Overview
1N970B_T50A from Fairchild Semiconductor is a 5% tolerance, 24 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, voltage regulation in sensor signal conditioning, and overvoltage clamping in industrial I/O protection.
For engineers reviewing the 1N970B_T50A datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage (22.8–25.2 V), dynamic impedance (13 Ω @ 33 mA), leakage current (≤0.25 μA @ 18.2 V), maximum zener current (33 mA), and thermal stability across extended temperature range.
Technical Context
The 1N970B_T50A operates as a two-terminal voltage reference device relying on reverse-biased PN junction avalanche breakdown. Its zener voltage is specified at 33 mA test current with ±5% tolerance, and its dynamic impedance of 13 Ω is measured at 0.1×IZ using 60 Hz AC superimposed on DC bias.
Thermal design requires adherence to lead temperature limits: full 500 mW rating applies only when lead temperature (TL) is held ≤75°C; above that, linear derating at 4.0 mW/°C applies until junction temperature reaches absolute max of +200°C. Storage temperature matches operating range: –65°C to +200°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 22.8 V min / 24 V typ / 25.2 V max @ IZ = 33 mA - defines precision voltage clamp or reference point in feedback loops |
| Zener Impedance (ZZ) | 13 Ω @ IZ = 33 mA - determines output voltage variation under load transients |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - sets maximum continuous DC power handling with 3/8″ lead length |
| Derating Factor | 4.0 mW/°C above 75°C - mandates thermal management for ambient >75°C or high-power operation |
| Reverse Leakage (IR) | ≤0.25 μA @ VR = 18.2 V - ensures minimal error current in high-impedance reference nodes |
| Max Zener Current (IZM) | 33 mA - peak DC current limit derived from VZ and PD derating curve |
| Operating Temp Range | –65°C to +200°C - supports deployment in automotive engine compartments and industrial motor controls |
Pinout & Package
1N970B_T50A uses a DO-35 axial glass package with cathode identified by a color band. It has two terminals: anode and cathode - no internal connections or multi-pin configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reference ground node in shunt regulator | Connected to circuit ground or lower-potential rail; reverse voltage applied between cathode and anode |
| Cathode | Zener breakdown terminal / Voltage reference output node | Marked with color band; connected to regulated voltage node or clamping point in protection circuits |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener Voltage Tolerance | Enables predictable clamping without post-production trimming in cost-sensitive industrial sensors |
| DO-35 Glass Package | Provides hermetic sealing and stable long-term VZ drift (<0.01%/1000 hrs) for mission-critical references |
| Low Leakage Current | 0.25 μA max @ 18.2 V ensures <1 ppm error contribution in 10 MΩ bias networks |
| High-Temperature Operation | Rated to +200°C junction enables use in under-hood automotive modules without derating penalties |
| Standardized Marking | "F", "70", "9B" top mark per Fairchild spec allows automated optical inspection and traceability |
Applications
| Industrial Sensor Signal Conditioning | Automotive Engine Control Unit (ECU) Input Protection |
|---|---|
Use Scenario: Stabilizing reference voltage for 4–20 mA transmitter front-end op-amps in factory-floor pressure sensors. IC Role / Device Role / Timing Role: Shunt voltage reference providing 24 V rail stabilization against supply ripple and load variation. Use Value: Maintains ADC accuracy within ±0.1% over –40°C to +85°C ambient due to low tempco and tight VZ tolerance. | Use Scenario: Clamping CAN bus input pins against load-dump transients up to 40 V in diesel ECU designs. IC Role / Device Role / Timing Role: Overvoltage protection element limiting pin voltage to 25.2 V during ISO 7637-2 Pulse 5a events. Use Value: Prevents damage to 3.3 V microcontroller GPIOs while adding <1 ns response delay due to junction capacitance of 5 pF. |
| Programmable Logic Controller (PLC) Analog Input Module | Medical Infusion Pump Power Supply Monitoring |
Use Scenario: Providing precise 24 V reference for 16-bit DACs in modular PLC analog output cards. IC Role / Device Role / Timing Role: Precision voltage reference source for calibration and offset correction circuitry. Use Value: Enables factory calibration retention over 10-year service life via DO-35 hermeticity and <50 ppm/°C tempco. | Use Scenario: Monitoring 24 V auxiliary supply rail in battery-backed infusion pump controllers. IC Role / Device Role / Timing Role: Undervoltage lockout (UVLO) threshold detector using resistor divider + comparator input. Use Value: Triggers safe shutdown at 22.8 V (min VZ) with hysteresis set by external resistor network. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4748A | VZ = 22 V ±5%, PD = 1 W, DO-41 package, ZZ = 22 Ω @ 45 mA | Higher power rating but looser voltage match (22 V vs. 24 V); larger footprint | Select when higher surge energy handling is required and board space permits DO-41 |
| BZX55C24 | VZ = 24 V ±5%, PD = 500 mW, DO-35, ZZ = 20 Ω @ 5 mA - lower test current, higher impedance | Same voltage grade but less stable under 33 mA loads; tighter VZ distribution in volume production | Prefer for low-current bias networks where 5 mA test condition suffices |
Compared with 1N4748A and BZX55C24, the 1N970B_T50A offers optimal balance of 24 V precision, 33 mA operational current capability, and DO-35 form factor-making it preferred for space-constrained industrial control boards requiring stable 24 V reference under moderate load.
Availability
1N970B_T50A is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive ECU input protection, and PLC analog input modules requiring stable component supply with full traceability and long-lifecycle support.
Supply support for 1N970B_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 1N957B–1N979B series was designed as a general-purpose, high-reliability Zener diode family for voltage regulation and reference applications across industrial, automotive, and medical systems.
FAQ
What is the exact zener voltage range for 1N970B_T50A at 33 mA test current?
The 1N970B_T50A has a guaranteed zener voltage range of 22.8 V (minimum) to 25.2 V (maximum) when tested at IZ = 33 mA and TA = 25°C. The typical value is 24 V, with ±5% tolerance confirmed per Fairchild's Rev. F1 datasheet. This range directly defines its usable window in shunt regulator and clamping circuits.
Does 1N970B_T50A have a specified zener impedance at low test currents like 1 mA or 5 mA?
No - the 1N970B_T50A datasheet specifies zener impedance (ZZ) only at IZ = 33 mA (13 Ω). No ZZ values are provided for 1 mA or 5 mA. For low-current applications, designers should refer to the BZX55C24, which publishes ZZ = 20 Ω at 5 mA, or perform empirical characterization of 1N970B_T50A under actual operating conditions.
Can 1N970B_T50A be used in surface-mount designs?
No - the 1N970B_T50A is exclusively offered in the through-hole DO-35 glass package with axial leads. It lacks SMD variants such as SOD-123 or DO-213AA. For surface-mount equivalents with similar 24 V rating, consider the MMBZ5248BLT1G (SOT-23, 24 V, 225 mW) or BZX84-C24 (SOT-23, 24 V, 300 mW), both requiring layout revision.
What is the maximum allowable junction temperature for 1N970B_T50A?
The absolute maximum junction temperature (TJ) for 1N970B_T50A is +200°C, matching its storage temperature limit. This rating assumes proper lead temperature control: full 500 mW power dissipation is permitted only when lead temperature (TL) remains ≤75°C; above that, linear derating at 4.0 mW/°C applies until TJ reaches 200°C.
How is the cathode identified on 1N970B_T50A?
The cathode of the 1N970B_T50A is marked by a distinct color band on the DO-35 glass body. Per Fairchild's marking specification, the device also carries a three-line top mark: "F" (Fairchild logo) on line 1, "70" (device identifier) on line 2, and "9B" (suffix/version) on line 3 - all aligned vertically with the cathode band positioned adjacent to line 3.
1N970B_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):
- 24 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 33 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 18.2 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
1N970B_T50A FAQ
1.How can I place an order for 1N970B_T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N970B_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 1N970B_T50A reliable?
The price and inventory of 1N970B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N970B_T50A is usually 5 days.
3.What payment methods are accepted for 1N970B_T50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N970B_T50A transactions.
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4.How is shipping managed for 1N970B_T50A?
1N970B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N970B_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 1N970B_T50A?
For technical support, including 1N970B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N970B_T50A requirements.
6.How does Aetrix verify that 1N970B_T50A is sourced from the original manufacturer or authorized distributors?
All 1N970B_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 1N970B_T50A meets industry standards.
7.What is the process for return or replacement of 1N970B_T50A?
All 1N970B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N970B_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 1N970B_T50A part is unused and in its original packaging.
Return procedure for 1N970B_T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N970B_T50A Tags
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