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Texas Instruments LM185BYH-2.5
- Part No.:
- LM185BYH-2.5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-46-2 Metal Can
- Datasheet:
-
LM185BYH-2.5.pdf
- Description:
- IC VREF SHUNT 1.5% TO2
- Quantity:
- Payment:
- Shipping:
Inventory:3,498
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Product details
Overview
LM185BYH-2.5 from Texas Instruments is a micropower 2-terminal band-gap voltage reference diode delivering a precise 2.5 V output with ±20 mV (±0.8%) initial tolerance (A grade), 0.6 Ω dynamic impedance, and operation over −55°C to +125°C - used in portable meters, battery-powered regulators, and precision analog circuitry where ultra-low quiescent current and long-term stability are critical.
For engineers reviewing the LM185BYH-2.5 datasheet, LM185BYH-2.5 pinout, LM185BYH-2.5 application, or LM185BYH-2.5 equivalent, key selection considerations include its wide 20 μA–20 mA operating current range, low temperature coefficient (≤50 ppm/°C for Y-grade), capacitive loading tolerance, and hermetic TO-package suitability for high-reliability industrial and aerospace systems.
Technical Context
The LM185BYH-2.5 implements a band-gap reference architecture using only transistors and resistors, enabling low noise (120 μV rms, 10 Hz–10 kHz) and excellent long-term stability (20 ppm over 1000 hours). Its on-chip trimming ensures tight initial voltage accuracy without external calibration.
Designed for extreme environmental resilience, it supports full military-grade temperature operation (−55°C to +125°C), features built-in ESD protection (2 kV HBM), and maintains regulation across wide supply variations - making it suitable for unregulated battery inputs and harsh-condition instrumentation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.5 V nominal, with ±20 mV (±0.8%) initial tolerance - enables direct replacement of older references while tightening system accuracy. |
| Operating Current Range | 20 μA to 20 mA - supports micropower standby (e.g., 30 μA in 9V battery references) and higher-current precision regulation without redesign. |
| Dynamic Impedance | 0.6 Ω at 100 μA - ensures minimal output voltage shift under load transients, critical for ADC reference and sensor biasing. |
| Temperature Coefficient | 50 ppm/°C (Y grade) - guarantees ≤1.25 mV drift over −55°C to +125°C, meeting requirements for calibrated test equipment. |
| Long-Term Stability | 20 ppm over 1000 hours - provides predictable aging behavior for systems requiring multi-year calibration intervals. |
| Wideband Noise | 120 μV rms (10 Hz–10 kHz) - low enough for 12-bit+ data acquisition without additional filtering. |
| Capacitive Loading Tolerance | Stable with unlimited capacitance - eliminates need for series isolation resistor in battery-monitoring or DAC reference applications. |
Pinout & Package
LM185BYH-2.5 is supplied in a hermetic TO package (package number NDU0002A), featuring axial leads and glass-sealed construction for moisture resistance and extended reliability in demanding environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink terminal | Connected to system ground or lower-potential node; reverse-biased operation requires current into this pin. |
| Cathode | Reference voltage output | Provides stable 2.5 V when reverse-biased; serves as precision voltage source for ADCs, op-amps, or comparator thresholds. |
Key Features
| Feature | Design Value |
|---|---|
| Micropower operation | Functional down to 20 μA - extends shelf life of battery-powered devices such as handheld calibrators and remote sensors. |
| Hermetic TO packaging | Sealed ceramic/metal construction - ensures long-term parameter stability and immunity to humidity-induced drift in aerospace or downhole tools. |
| Tight initial tolerance | ±20 mV (±0.8%) at 25°C - reduces or eliminates need for post-assembly trimming in production test fixtures. |
| Low dynamic impedance | 0.6 Ω - maintains reference accuracy during fast-switching load events, e.g., SAR ADC sampling bursts. |
| High-temperature rating | −55°C to +125°C operating range - qualified for engine control units, avionics power supplies, and industrial PLC modules. |
Applications
| Portable Precision Meters | Battery-Powered Sensor Nodes |
|---|---|
Use Scenario: Handheld multimeters and calibration standards operating from 9V alkaline batteries with >10-year shelf life requirements. IC Role / Device Role / Timing Role: Primary 2.5 V reference for 16-bit delta-sigma ADC and LCD bias generation. Use Value: 20 μA minimum operating current enables microamp-level sleep modes; hermetic TO package prevents humidity-induced voltage drift over field deployment. |
Use Scenario: Wireless temperature/humidity nodes powered by coin-cell batteries with 5+ year operational lifetime. IC Role / Device Role / Timing Role: Stable reference for RTD-to-digital signal chain and low-power MCU ADC. Use Value: 50 ppm/°C tempco ensures <±0.5°C measurement error across −40°C to +85°C ambient; 20 ppm/1000 hr aging minimizes recalibration frequency. |
| Aerospace Power Monitoring | Industrial Process Transmitters |
Use Scenario: DC bus voltage monitoring in satellite power distribution units exposed to thermal cycling and radiation. IC Role / Device Role / Timing Role: Reference for isolated shunt-based current sensing and fault-detection comparators. Use Value: −55°C to +125°C rating and hermetic sealing meet MIL-PRF-38534 Class H requirements; 2 kV HBM ESD rating withstands handling in cleanroom assembly. |
Use Scenario: 4–20 mA loop-powered pressure transmitters installed in chemical plant environments with wide ambient swings. IC Role / Device Role / Timing Role: Precision reference for voltage-to-current conversion and sensor excitation. Use Value: 0.6 Ω dynamic impedance rejects ripple from switching regulators; capacitive loading tolerance simplifies PCB layout near noisy motor drives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BYZ-2.5/NOPB | Same 2.5 V Y-grade reference, but TO-92 molded plastic package; rated 0°C to +70°C; 50 ppm/°C tempco. | Lower-cost commercial-grade alternative; unsuitable for extended temperature or hermetic reliability requirements. | Select for cost-sensitive industrial controls where full military temp range and hermeticity are unnecessary. |
| REF3025AIDBZR | 2.5 V precision reference in SOT-23; 0.2% initial accuracy; 50 ppm/°C max tempco; 50 μA typical IQ; specified for −40°C to +125°C. | Surface-mount solution with tighter initial tolerance but higher quiescent current; no hermetic option. | Choose when board space is constrained and RoHS-compliant surface-mount assembly is required, accepting trade-off in ultra-low IQ. |
Compared with LM385BYZ-2.5/NOPB, LM185BYH-2.5 offers superior temperature range and hermetic reliability at the cost of larger through-hole footprint; versus REF3025AIDBZR, it delivers lower operating current and proven long-term stability but lacks modern CMOS process advantages like tighter initial tolerance and integrated enable.
Availability
LM185BYH-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, aerospace power monitoring, and industrial process transmitters requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for LM185BYH-2.5 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
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of heritage in precision analog design and high-reliability component manufacturing.
LM185BYH-2.5 belongs to TI's legacy micropower voltage reference family, engineered specifically for applications demanding ultra-low current consumption, wide temperature operation, and hermetic packaging - including military, aerospace, and industrial instrumentation.
FAQ
What is the operating temperature range of the LM185BYH-2.5?
The LM185BYH-2.5 is rated for continuous operation from −55°C to +125°C. This full military-grade temperature range is enabled by its hermetic TO package and internal band-gap design, making it suitable for engine compartments, avionics bays, and downhole tools where ambient extremes are routine. The LM185BYH-2.5 maintains specified electrical performance across this entire range without derating.
Is the LM185BYH-2.5 pin-compatible with other LM185-2.5 variants?
No - LM185BYH-2.5 uses a hermetic TO package (NDU0002A) with axial leads, whereas LM185-2.5-N in TO-92 (LP0003A) or SOIC (D0008A) has different pin geometry and mounting. While all share identical electrical functionality as 2-terminal references, mechanical compatibility requires matching package type. The "H" suffix in LM185BYH-2.5 explicitly denotes the hermetic TO variant.
What does the "BY" in LM185BYH-2.5 signify?
The "BY" suffix identifies the LM185BYH-2.5 as the Y-grade version: it guarantees a maximum temperature coefficient of 50 ppm/°C and ±20 mV (±0.8%) initial voltage tolerance at 25°C. This grade is distinct from "BX" (30 ppm/°C) and standard "B" (150 ppm/°C), reflecting tighter factory trimming for high-accuracy applications.
Can the LM185BYH-2.5 be used with large output capacitors?
Yes - the LM185BYH-2.5 is explicitly designed for exceptional capacitive loading tolerance, remaining stable with unlimited output capacitance. This eliminates the need for series isolation resistors often required with other references, simplifying design in battery-backed systems and reducing component count in portable meter front-ends where bulk decoupling is essential.
Why is the LM185BYH-2.5 marked 'Not Recommended For New Designs'?
The LM185BYH-2.5 is flagged "Not Recommended For New Designs" due to TI's strategic shift toward newer, smaller-footprint references (e.g., REF30xx series), not because of obsolescence or reliability concerns. It remains in active production with full datasheet support, long-term availability commitments, and unchanged specifications - ideal for legacy system refreshes, high-reliability upgrades, and applications where hermetic TO packaging is mandatory.
LM185BYH-2.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-46-2 Metal Can
- Series:
- -
- Packaging:
- Box
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1.5%
- Temperature Coefficient:
- 50ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 120µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 20 µA
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-2
LM185BYH-2.5 FAQ
1.How can I place an order for LM185BYH-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM185BYH-2.5 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 LM185BYH-2.5 reliable?
The price and inventory of LM185BYH-2.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM185BYH-2.5 is usually 5 days.
3.What payment methods are accepted for LM185BYH-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM185BYH-2.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM185BYH-2.5?
LM185BYH-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM185BYH-2.5 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 LM185BYH-2.5?
For technical support, including LM185BYH-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM185BYH-2.5 requirements.
6.How does Aetrix verify that LM185BYH-2.5 is sourced from the original manufacturer or authorized distributors?
All LM185BYH-2.5 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 LM185BYH-2.5 meets industry standards.
7.What is the process for return or replacement of LM185BYH-2.5?
All LM185BYH-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM185BYH-2.5, 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 LM185BYH-2.5 part is unused and in its original packaging.
Return procedure for LM185BYH-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM185BYH-2.5 Tags
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