My Inquiry
My Account
Microchip Technology 1N4490US/TR
- Part No.:
- 1N4490US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, A
- Datasheet:
-
1N4490US/TR.pdf
- Description:
- DIODE ZENER 110V 1.5W D5A
- Quantity:
- Payment:
- Shipping:
Inventory:100
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4490US/TR from Microsemi is a hermetically sealed, voidless glass MELF (D-5A) surface-mount Zener diode rated for 1.5 W steady-state power dissipation, with nominal Zener voltage of 110 V at 2.3 mA test current, ±5% tolerance, and maximum dynamic impedance of 300 Ω at IZT. It operates across –65 °C to +175 °C junction temperature and is qualified to MIL-PRF-19500/406 at JANTXV level for high-reliability voltage regulation in aerospace power conditioning circuits.
For engineers reviewing the 1N4490US/TR datasheet, 1N4490US/TR pinout, 1N4490US/TR application, or 1N4490US/TR equivalent, this page delivers verified electrical parameters, military-grade qualification status, thermal derating behavior, package dimensions, and direct alternatives for ruggedized analog reference and overvoltage protection designs.
Technical Context
This device functions as a precision voltage reference and shunt regulator in high-stability analog subsystems, leveraging its hermetic voidless glass construction and Category I internal metallurgical bond to ensure long-term parameter stability under thermal cycling and radiation exposure. Its 110 V Zener voltage is specified at 2.3 mA IZT, with knee impedance (ZZK) of 4000 Ω at IZK = 0.25 mA and reverse leakage ≤0.25 µA at 88 V.
The 1N4490US/TR exhibits a negative temperature coefficient above ~5 V, with typical TC near –0.05 %/°C at 110 V per Figure 1, and follows MIL-PRF-19500/406 thermal derating curves - full 1.5 W rating applies only at TA = 25 °C, dropping linearly to zero at 175 °C per Figure 2.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 110 V nominal at IZT = 2.3 mA - defines stable regulation point for high-voltage reference rails. |
| Power Dissipation (PD) | 1.5 W at TA = 25 °C - sets maximum continuous DC power handling before thermal derating applies. |
| Dynamic Impedance (ZZT) | 300 Ω at IZT = 2.3 mA - determines output voltage variation under load current changes. |
| Max Reverse Leakage (IR) | 0.25 µA at VR = 88 V - ensures minimal error current in high-impedance bias networks. |
| Junction Temperature Range | –65 °C to +175 °C - enables operation in extreme environments including space and engine bay electronics. |
| Tolerance | ±5% (no suffix) - standard accuracy grade suitable for non-critical regulation where cost and availability are prioritized. |
| Package | D-5A MELF - cylindrical surface-mount glass package with cathode band marking and Sn/Pb terminations. |
Pinout & Package
The 1N4490US/TR uses a two-terminal MELF (D-5A) glass package with no leads: cathode is marked by a single dark band; anode is unmarked end. Terminals are tin/lead (Sn/Pb) over copper, RoHS-compliant versions available for commercial grade only.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Zener breakdown terminal | Connected to regulated voltage node; reverse-biased during normal operation. |
| Anode (unmarked end) | Reference return path | Connected to system ground or lower-potential rail; completes Zener conduction path. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass seal | Prevents moisture ingress and parametric drift over 20+ year field life in humid or vacuum environments. |
| Category I metallurgical bond | Ensures mechanical robustness and low interfacial resistance between silicon die and tungsten slug under shock/vibration. |
| MIL-PRF-19500/406 JANTXV qualification | Validates performance across screening, burn-in, and environmental stress tests required for flight-critical systems. |
| Triple-layer passivation | Reduces surface leakage and enhances long-term stability of Zener voltage under high humidity and bias stress. |
| Non-ESD-sensitive (MIL-STD-750 Method 1020) | Eliminates need for ESD handling protocols during board assembly and rework. |
Applications
| Avionics Power Monitoring | Satellite Bus Voltage Reference |
|---|---|
Use Scenario: Monitoring 100 V primary bus voltage in airborne mission computers using resistive divider + comparator. IC Role / Device Role / Timing Role: Shunt Zener reference providing stable 110 V threshold for overvoltage detection circuitry. Use Value: Maintains ±5% regulation accuracy across –55 °C to +125 °C operating range without calibration drift. |
Use Scenario: Generating precision bias for radiation-hardened op-amps in LEO satellite telemetry front-ends. IC Role / Device Role / Timing Role: High-stability voltage reference source for analog-to-digital converter reference buffers. Use Value: Hermetic seal and inherent radiation hardness (per MicroNote 050) prevent parameter shift in total ionizing dose environments. |
| Downhole Oilfield Instrumentation | Military Radar Pulse Modulator |
Use Scenario: Regulating auxiliary supply for MEMS pressure sensors deployed at 175 °C wellbore temperatures. IC Role / Device Role / Timing Role: High-temperature Zener clamp protecting downstream regulators from transient overvoltage events. Use Value: Guaranteed operation up to +175 °C junction temperature with no derating loss below 150 °C ambient. |
Use Scenario: Providing stable gate bias for high-voltage MOSFET stacks in pulsed RF amplifier modulators. IC Role / Device Role / Timing Role: Precision voltage clamp limiting gate drive swing to prevent device avalanche failure. Use Value: Low dynamic impedance (300 Ω) ensures fast response to nanosecond-scale transients during pulse edges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4490US | Same electrical specs and package; differs only in packaging format (bulk vs. tape-and-reel). | No functional difference; 1N4490US/TR is optimized for automated SMT placement. | Select 1N4490US/TR when requiring EIA-481-B compliant tape-and-reel delivery for high-volume production. |
| SMF110A | Surface-mount SOD-123 package, 1.0 W rating, ±5% tolerance, 110 V VZ, but not MIL-qualified or hermetically sealed. | Limited to commercial-grade industrial applications; unsuitable for aerospace or radiation-exposed use. | Choose SMF110A only for cost-sensitive, non-military designs where hermeticity and extended temperature range are not required. |
Compared with 1N4490US/TR, the 1N4490US offers identical performance in bulk form but lacks reel packaging logistics, while SMF110A trades military reliability and thermal margin for lower cost and smaller footprint in benign environments.
Availability
1N4490US/TR is available at Aetrix Electronics and suitable for avionics power monitoring, satellite bus voltage reference, and downhole oilfield instrumentation requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N4490US/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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components for defense, aerospace, and industrial markets.
The 1N4490US/TR belongs to Microsemi's legacy MIL-PRF-19500/406 qualified Zener diode family, engineered specifically for voltage regulation in mission-critical systems where failure is not an option.
FAQ
What is the Zener voltage tolerance for 1N4490US/TR?
The 1N4490US/TR has a standard ±5% Zener voltage tolerance, as indicated by the absence of a tolerance suffix in the part number. This means its actual VZ falls between 104.5 V and 115.5 V when measured at IZT = 2.3 mA and TA = 25 °C. Tighter tolerances (±2% or ±1%) require different suffixes (C or D) and are not applicable to the 1N4490US/TR variant.
Is 1N4490US/TR suitable for space applications?
Yes, the 1N4490US/TR is suitable for space applications due to its JANTXV qualification per MIL-PRF-19500/406, hermetic voidless glass construction, triple-layer passivation, and documented radiation hardness per Microsemi MicroNote 050. Its guaranteed operation from –65 °C to +175 °C supports deployment in LEO and GEO satellite power systems.
What is the maximum surge current rating for 1N4490US/TR?
The 1N4490US/TR has a non-repetitive peak Zener surge current (IZSM) rating of 0.13 A for an 8.3 ms square wave pulse, as specified in the Electrical Characteristics table on page 3 of the datasheet. This value reflects safe single-event energy absorption capability beyond steady-state limits.
Does 1N4490US/TR have RoHS-compliant termination options?
RoHS-compliant matte tin terminations are available for the 1N4490US/TR, but only in commercial-grade versions - not for JAN, JANTX, JANTXV, or JANS reliability levels. The standard 1N4490US/TR uses Sn/Pb terminations; RoHS variants must be explicitly ordered with e3 suffix per nomenclature rules.
How does thermal derating affect 1N4490US/TR power handling?
The 1N4490US/TR's 1.5 W power rating applies only at TA = 25 °C. Per Figure 2, power must be linearly derated to zero at +175 °C junction temperature - resulting in ~1.0 W max at 75 °C ambient and ~0.5 W at 125 °C ambient. Derating is mandatory to avoid exceeding TJ = 175 °C under sustained load.
1N4490US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, A
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 110 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 300 Ohms
- Current - Reverse Leakage @ Vr:
- 250 nA @ 88 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:
- D-5A
1N4490US/TR FAQ
1.How can I place an order for 1N4490US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4490US/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 1N4490US/TR reliable?
The price and inventory of 1N4490US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4490US/TR is usually 5 days.
3.What payment methods are accepted for 1N4490US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4490US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4490US/TR?
1N4490US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4490US/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 1N4490US/TR?
For technical support, including 1N4490US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4490US/TR requirements.
6.How does Aetrix verify that 1N4490US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4490US/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 1N4490US/TR meets industry standards.
7.What is the process for return or replacement of 1N4490US/TR?
All 1N4490US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4490US/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 1N4490US/TR part is unused and in its original packaging.
Return procedure for 1N4490US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4490US/TR 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
