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Microchip Technology 1N989B
- Part No.:
- 1N989B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AA, DO-7, Axial
- Datasheet:
-
1N989B.pdf
- Description:
- DIODE ZENER 150V 500MW DO7
- Quantity:
- Payment:
- Shipping:
Inventory:8,590
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Product details
Overview
1N989B from Microsemi is a silicon 500 mW axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 150 V nominal Zener voltage at ±5% tolerance, 0.85 mA test current, and +0.11 %/°C temperature coefficient. It operates across –65°C to +175°C and delivers stable voltage regulation in low-power reference and protection circuits.
For engineers reviewing the 1N989B datasheet, 1N989B pinout, 1N989B application, or 1N989B equivalent, key selection criteria include its 150 V Zener voltage, 0.85 mA IZT, 1500 Ω ZZT, 2.4 mA maximum DC Zener current (IZM), and DO-35 mechanical compatibility with axial-leaded PCB layouts.
Technical Context
The 1N989B functions as a two-terminal voltage reference device, operating in reverse breakdown mode with cathode band indicating polarity. Its Zener impedance of 1500 Ω at 0.85 mA reflects moderate dynamic resistance suitable for non-critical biasing and clamping.
It exhibits a positive temperature coefficient of +0.11 %/°C - consistent with higher-voltage Zeners (>100 V) in the 1N957B–1N992B family - and maintains regulation over wide temperature extremes (–65°C to +175°C) without derating below 50°C lead temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 150 V ±5% - defines regulated output voltage under specified test conditions |
| Zener Test Current | 0.85 mA - minimum current required to achieve rated VZ; impacts bias network design |
| Zener Impedance | 1500 Ω @ IZT - determines voltage deviation under load current variation |
| Max DC Zener Current | 2.4 mA - sets upper limit for continuous regulation without exceeding 400 mW dissipation at 75°C |
| Temp Coefficient | +0.11 %/°C - quantifies VZ drift per degree Celsius rise; enables thermal error budgeting |
| Power Dissipation | 500 mW @ TL < 50°C - specifies absolute max steady-state power at defined lead temperature |
| Reverse Leakage | 5 μA @ 114 V - ensures minimal off-state current when used as clamp below breakdown |
Pinout & Package
Package: DO-35 (DO-204AH), hermetically sealed glass axial-leaded case with tin-lead or RoHS-compliant matte-tin plating; cathode identified by colored band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node during Zener operation; forward voltage ≤1.3 V @ 200 mA |
| Cathode | Banded end | Connected to higher-potential node; reverse-biased to enable Zener breakdown regulation |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N989B | Ensures standardized electrical behavior and interchangeability across qualified suppliers |
| ±5% Zener voltage tolerance (B suffix) | Reduces need for post-production trimming in cost-sensitive voltage reference designs |
| –65°C to +175°C operating range | Supports deployment in aerospace, downhole, and industrial environments without external thermal management |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates requirement for handling precautions or on-board ESD protection circuitry |
| Hermetic glass DO-35 package | Provides long-term reliability and moisture resistance superior to plastic-packaged alternatives |
Applications
| Industrial Power Supply Monitoring | Aerospace Sensor Biasing |
|---|---|
Use Scenario: Monitoring intermediate rail voltages in 24 V or 48 V industrial SMPS to trigger overvoltage shutdown. IC Role / Device Role / Timing Role: Two-terminal shunt regulator providing precise 150 V reference threshold for comparator input. Use Value: Leverages 150 V rating and +0.11 %/°C TC to maintain trip-point accuracy across –40°C to +85°C ambient without calibration. | Use Scenario: Establishing stable bias voltage for radiation-hardened op-amps in satellite attitude control sensors. IC Role / Device Role / Timing Role: Passive voltage reference enabling low-drift analog front-end conditioning in high-reliability signal chains. Use Value: Uses inherent radiation hardness and –65°C to +175°C operation to sustain performance in LEO orbital thermal cycles. |
| Test Equipment Calibration Reference | High-Voltage Clamp Protection |
Use Scenario: Serving as traceable 150 V reference in portable multimeter calibration fixtures. IC Role / Device Role / Timing Role: Precision shunt element in feedback loop of adjustable reference generator. Use Value: Delivers ±5% initial accuracy and predictable TC for field-serviceable calibration without active compensation. | Use Scenario: Clamping transient surges on 120 V AC-derived DC rails in motor drive gate driver supplies. IC Role / Device Role / Timing Role: Overvoltage protector limiting peak voltage to 150 V during line transients. Use Value: Withstands 12 A surge current (1/120 sec) and maintains <5 μA leakage at 114 V, ensuring low standby loss. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4745A | 16 V Zener voltage, 1 W power rating, DO-41 package, ±5% tolerance | Lower voltage, higher power; unsuitable for 150 V reference but better for 16 V rail clamping | Select only if target regulation voltage is near 16 V and board space allows DO-41 footprint |
| MMBZ5267B | 100 V Zener voltage, SOT-23 surface-mount, 225 mW, ±5% tolerance | Surface-mount form factor, lower voltage, reduced power; incompatible with 150 V requirement | Choose for space-constrained PCBs where 100 V regulation suffices and reflow assembly is preferred |
Compared with 1N989B, 1N4745A offers higher power but cannot replace it in 150 V applications, while MMBZ5267B provides SMT convenience at the cost of voltage rating and power capability - neither is a direct substitute, but both serve adjacent voltage tiers in Zener-based designs.
Availability
1N989B is available at Aetrix Electronics and suitable for industrial power monitoring, aerospace sensor biasing, test equipment calibration, and high-voltage clamp protection requiring stable component supply and long-lifecycle support.
Supply support for 1N989B 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and high-voltage analog components.
The 1N957B–1N992B series was designed specifically for ruggedized voltage regulation in military, aerospace, and industrial systems where extended temperature operation and hermetic packaging are mandatory.
FAQ
What is the Zener voltage tolerance for 1N989B?
The 1N989B has a nominal Zener voltage of 150 V with a tolerance of ±5%, indicated by the "B" suffix per JEDEC standard. This tolerance applies at 25°C with 0.85 mA test current and defines the allowable initial variation before thermal or aging effects.
Can 1N989B be used in surface-mount designs?
No - the 1N989B is packaged in the axial-leaded DO-35 (DO-204AH) glass case and requires through-hole mounting. For surface-mount equivalents, Microsemi offers the MLL989B in DO-213AA (MELF) package, which shares identical electrical specs but different mechanical form.
What is the maximum surge current rating for 1N989B?
The 1N989B supports a maximum surge current (IZSM) of 12 A for a 1/120 second duration, as specified in the datasheet. This rating applies to square-wave or half-sine wave pulses and enables transient overvoltage clamping in power supply protection circuits.
Does 1N989B require heatsinking in typical applications?
No - the 1N989B is rated for 500 mW at lead temperature <50°C and dissipates only up to 400 mW continuously at 75°C. In standard PCB mounting (FR4, 4 mm² copper pads), its thermal resistance (310°C/W) keeps junction temperature within limits without added heatsinking for IZ ≤ 2.4 mA.
Is 1N989B RoHS compliant?
Yes - the base 1N989B is not RoHS compliant, but the RoHS-compliant version is designated 1N989Be3, where the "e3" suffix indicates annealed matte-tin plating per JEDEC standards. Always verify suffix when ordering for compliance-critical programs.
1N989B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AA, DO-7, Axial
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- 150 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 1500 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 114 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-7
1N989B FAQ
1.How can I place an order for 1N989B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N989B 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 1N989B reliable?
The price and inventory of 1N989B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N989B is usually 5 days.
3.What payment methods are accepted for 1N989B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N989B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N989B?
1N989B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N989B 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 1N989B?
For technical support, including 1N989B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N989B requirements.
6.How does Aetrix verify that 1N989B is sourced from the original manufacturer or authorized distributors?
All 1N989B 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 1N989B meets industry standards.
7.What is the process for return or replacement of 1N989B?
All 1N989B units undergo pre-shipment inspection (PSI). If there is an issue with 1N989B, 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 1N989B part is unused and in its original packaging.
Return procedure for 1N989B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N989B 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
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