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Microchip Technology 1N4988US/TR
- Part No.:
- 1N4988US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
1N4988US/TR.pdf
- Description:
- DIODE ZENER 180V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:68
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Product details
Overview
1N4988US/TR from Microsemi is a surface-mount, voidless-hermetically-sealed glass Zener diode rated for 5 W power dissipation at TEC = 125 °C, with nominal Zener voltage of 180 V ±5%, dynamic impedance of 450 Ω at IZT = 5 mA, and maximum reverse leakage current of 2 μA at VR = 144 V - used in high-reliability voltage regulation and overvoltage protection circuits for aerospace power supplies.
For engineers reviewing the 1N4988US/TR datasheet, 1N4988US/TR pinout, 1N4988US/TR application, or 1N4988US/TR equivalent, this part supports MIL-PRF-19500/356 qualified designs requiring extended temperature operation (–65 °C to +175 °C), radiation-hardened behavior, and robust surge immunity in mission-critical analog power conditioning.
Technical Context
This Zener regulator operates in reverse breakdown with tightly controlled voltage regulation across wide current (10%–50% of IZM) and temperature ranges. Its voidless-glass hermetic seal and Category III internal metallurgical bond ensure long-term stability under thermal cycling and mechanical stress.
It delivers 180 V nominal regulation with ±5% tolerance, 450 Ω dynamic impedance at 5 mA test current, and <2 μA leakage at 144 V - enabling precise clamping in high-voltage bias networks and reference stabilization where drift must remain below 0.11%/°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 180 V ±5% at IZT = 5 mA - defines stable regulation point for high-voltage reference and clamp circuits. |
| Power Dissipation | 5 W @ TEC = 125 °C - enables sustained operation in compact, conduction-cooled power modules. |
| Dynamic Impedance (ZZ) | 450 Ω @ IZT = 5 mA - determines output voltage variation under load transients in feedback networks. |
| Reverse Leakage (IR) | 2 μA max @ VR = 144 V - ensures minimal parasitic current in high-impedance sensing paths. |
| Temp. Coefficient (αVZ) | +0.110 %/°C - quantifies voltage drift per degree Celsius for thermal error budgeting in precision systems. |
| Max. Surge Current (IZSM) | 1.2 A @ 8.3 ms square wave - withstands transient overvoltage events without degradation. |
| Operating Temperature | –65 °C to +175 °C - supports deployment in space-grade and downhole electronics without derating. |
Pinout & Package
Package: Hermetically sealed voidless hard glass case with tungsten slugs; end caps are copper with Sn/Pb finish; polarity indicated by cathode band; "E" package (also known as "D-5B").
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side connection | Connected to circuit ground or lower potential node during normal Zener operation. |
| Cathode | Reverse-biased breakdown terminal / high-side connection | Connected to regulated voltage rail; marked by visible band on glass body. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Eliminates moisture ingress and internal delamination risk over 20+ year field life in harsh environments. |
| Category III metallurgical bond | Ensures mechanical integrity under shock/vibration up to 100 g and thermal cycling beyond 1000 cycles. |
| MIL-PRF-19500/356 qualification | Validated for JAN, JANTX, JANTXV, and JANS screening levels - required for defense and space programs. |
| Nonsensitive to ESD | Withstands >4 kV HBM per MIL-STD-750 Method 1020 - no external protection needed in assembly handling. |
| Inherent radiation hardness | Qualified to 100 krad(Si) TID per MicroNote 050 - suitable for low-earth orbit satellite power subsystems. |
Applications
| Aerospace Power Conditioning | Downhole Instrumentation Bias |
|---|---|
Use Scenario: Regulating auxiliary supply rails in satellite DC-DC converters exposed to thermal vacuum and radiation. IC Role / Device Role / Timing Role: Zener voltage reference and overvoltage clamp in isolated feedback loops. Use Value: Maintains 180 V reference stability within ±0.11%/°C drift and survives 100 krad(Si) total ionizing dose. |
Use Scenario: Providing stable bias voltage for sensor front-ends in oil/gas well logging tools operating at 175 °C. IC Role / Device Role / Timing Role: High-temperature voltage reference in analog signal chains. Use Value: Operates continuously from –65 °C to +175 °C with <2 μA leakage at 144 V, ensuring measurement accuracy. |
| Military Radar HV Supplies | Nuclear Monitoring Systems |
Use Scenario: Clamping transient spikes on pulse modulator rails in ground-based radar transmitters. IC Role / Device Role / Timing Role: Surge-absorbing Zener limiter in high-power RF amplifier bias networks. Use Value: Withstands 1.2 A non-repetitive surge (8.3 ms) without parameter shift or bond failure. |
Use Scenario: Stabilizing detector bias in radiation-hardened nuclear instrumentation deployed in reactor containment zones. IC Role / Device Role / Timing Role: Radiation-tolerant voltage reference in safety-critical monitoring circuits. Use Value: Inherently hardened to 100 krad(Si); no additional shielding or derating required for long-term reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4988US | Same electrical specs and package; differs only in tape-and-reel packaging (TR suffix denotes reel format). | No functional difference - identical use in automated SMT assembly lines. | Select 1N4988US/TR when ordering for pick-and-place production; 1N4988US for sample evaluation or manual soldering. |
| 1N4987US/TR | 160 V nominal Zener voltage (vs. 180 V), same 5 W rating, 350 Ω ZZ, and –65 °C to +175 °C range. | Suitable where lower clamping threshold is acceptable, e.g., intermediate-stage regulation before final 180 V rail. | Choose 1N4987US/TR if system margin allows 20 V lower regulation; retains identical thermal and radiation performance. |
Compared with 1N4988US/TR, 1N4987US/TR offers 20 V lower regulation with identical ruggedness and temperature range, while 1N4988US shares all electrical and mechanical properties but omits tape-and-reel packaging - making TR the default for volume SMT deployment.
Availability
1N4988US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, downhole instrumentation bias, and military radar HV supplies requiring stable component supply with full traceability and long-lifecycle support.
Supply support for 1N4988US/TR 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 military-qualified components.
The 1N49xxUS series belongs to Microsemi's legacy high-power Zener family designed specifically for MIL-PRF-19500/356-compliant applications demanding extreme environmental resilience and long-term parametric stability.
FAQ
What is the Zener voltage tolerance for 1N4988US/TR?
The 1N4988US/TR has a nominal Zener voltage of 180 V with a standard tolerance of ±5%, as specified in the Microsemi SD44A datasheet. No suffix indicates this standard tolerance; tighter tolerances (e.g., ±2% or ±1%) require C or D suffixes not present in this part number. This tolerance directly impacts regulation accuracy in high-voltage reference circuits.
Does 1N4988US/TR require derating above 125 °C?
Yes - the 1N4988US/TR is rated for 5 W power dissipation only at TEC = 125 °C. Above that temperature, power must be linearly derated to zero at +175 °C, yielding a derating factor of 100 mW/°C. This is critical for thermal design in sealed enclosures or high-ambient environments like downhole tools.
Is 1N4988US/TR compatible with lead-free reflow processes?
No - the 1N4988US/TR features copper end caps with Sn/Pb (tin/lead) finish, making it incompatible with Pb-free reflow profiles. It is intended for SnPb soldering processes per J-STD-020. For RoHS-compliant alternatives, consult Microchip's current-generation Zener offerings, as this part remains designated for legacy high-reliability programs.
What is the maximum reverse leakage current for 1N4988US/TR?
The maximum reverse leakage current for 1N4988US/TR is 2 μA at VR = 144 V and TA = 25 °C, per the SD44A datasheet. This low leakage ensures minimal loading on high-impedance bias networks and preserves accuracy in precision voltage references used in sensor interfaces and telemetry systems.
How is polarity identified on the 1N4988US/TR glass body?
Polarity on the 1N4988US/TR is indicated by a visible cathode band on the glass envelope - the banded end is the cathode, and the unmarked end is the anode. This marking is consistent across the 1N49xxUS series and aligns with JEDEC-standard Zener diode orientation for surface-mount placement verification.
1N4988US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, E
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 180 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 450 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 136.8 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 1 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- E-MELF
1N4988US/TR FAQ
1.How can I place an order for 1N4988US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4988US/TR 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 1N4988US/TR reliable?
The price and inventory of 1N4988US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4988US/TR is usually 5 days.
3.What payment methods are accepted for 1N4988US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4988US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4988US/TR?
1N4988US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4988US/TR 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 1N4988US/TR?
For technical support, including 1N4988US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4988US/TR requirements.
6.How does Aetrix verify that 1N4988US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4988US/TR 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 1N4988US/TR meets industry standards.
7.What is the process for return or replacement of 1N4988US/TR?
All 1N4988US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4988US/TR, 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 1N4988US/TR part is unused and in its original packaging.
Return procedure for 1N4988US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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