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Texas Instruments LM185BYH1.2-SMD
- Part No.:
- LM185BYH1.2-SMD
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-46-2 Metal Can
- Datasheet:
-
LM185BYH1.2-SMD.pdf
- Description:
- IC VREF SHUNT 1.2V TO46-2
- Quantity:
- Payment:
- Shipping:
Inventory:3,377
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Product details
Overview
LM185BYH1.2-SMD from Texas Instruments is a micropower 2-terminal band-gap voltage reference diode delivering 1.223 V to 1.247 V reverse breakdown voltage at 10 µA, with ≤1 Ω typical dynamic impedance and ±50 ppm/°C temperature coefficient across −55°C to +125°C. It operates over 10 µA–20 mA current range and supports radiation-hardened applications up to 100 krad(Si).
For engineers reviewing the LM185BYH1.2-SMD datasheet, LM185BYH1.2-SMD pinout, LM185BYH1.2-SMD application, or LM185BYH1.2-SMD equivalent, key selection criteria include low-drift micropower reference stability in space-grade analog circuits, radiation tolerance verification, and TO-206AA (NDU) package compatibility for high-reliability PCB layouts.
Technical Context
The LM185BYH1.2-SMD implements a band-gap reference architecture using only transistors and resistors-enabling low noise, excellent long-term stability, and exceptional tolerance to capacitive loading. Its on-chip trimming achieves tight initial voltage tolerance without external calibration.
It functions as a 2-terminal device with reverse-bias operation: cathode connected to higher potential, anode to lower potential. Electrical behavior is defined by reverse breakdown voltage (VRef) and its variation with current (ΔVRef/ΔIR) and temperature (TC), not forward conduction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.223 V to 1.247 V at 10 µA - ensures precision biasing in low-power analog signal chains |
| Dynamic Impedance | ≤1 Ω typical - minimizes output voltage perturbation under load transients |
| Temp Coefficient | ±50 ppm/°C - guarantees <±0.006 V drift over full −55°C to +125°C operating range |
| Operating Current | 10 µA to 20 mA - enables use from ultra-low-power battery sensors to moderate-current regulators |
| Radiation Tolerance | 100 krad(Si) total ionizing dose - qualified for space and nuclear instrumentation environments |
| Max Junction Temp | +150°C - supports operation in sealed enclosures or high-ambient industrial settings |
| Thermal Resistance | 300°C/W (still air, TO package) - defines safe power dissipation limit at elevated ambient temperatures |
Pinout & Package
LM185BYH1.2-SMD uses the TO-206AA (NDU0002A) metal-can package: hermetically sealed, 2-pin, axial-leaded, with cathode marked by case notch. Package height ≤2.67 mm, diameter ≤5.44 mm, lead spacing 2.54 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reference ground terminal | Connected to system GND or lowest potential node; establishes return path for reference current |
| Cathode | Reference output terminal | Provides stable 1.2 V reference voltage when reverse-biased; must be held at higher potential than anode |
Key Features
| Feature | Design Value |
|---|---|
| Micropower operation | Functional down to 10 µA supply current - extends battery life in portable meters and remote sensors |
| Low dynamic impedance | ≤1 Ω typical - maintains regulation accuracy despite rapid load current changes |
| Tight initial tolerance | ±1.0% VRef (1.223–1.247 V at 10 µA) - reduces need for post-assembly trimming in production |
| Radiation qualification | 100 krad(Si) TID tested per MIL-STD-883 Method 1019 - validated for satellite avionics and reactor monitoring |
| Capacitive load immunity | No oscillation with ≥1 µF output capacitance - simplifies filtering without external compensation |
Applications
| Portable Precision Meters | Spacecraft Power Monitoring |
|---|---|
Use Scenario: Handheld multimeters and calibration standards powered by 9 V batteries requiring multi-year shelf-life operation. IC Role / Device Role / Timing Role: 2-terminal voltage reference providing stable excitation for ADCs and analog front-ends. Use Value: 10 µA minimum operating current enables >10-year battery life; ±50 ppm/°C TC ensures accuracy across field temperature swings. | Use Scenario: Onboard telemetry systems in LEO satellites where radiation-induced parameter shift must remain within spec. IC Role / Device Role / Timing Role: Primary reference for DC-DC converter feedback loops and sensor signal conditioning. Use Value: Post-100 krad(Si) ΔVRef limited to ±3% ensures continued regulation integrity after mission-critical radiation exposure. |
| Nuclear Instrumentation | High-Reliability Thermometry |
Use Scenario: Radiation survey dosimeters deployed in reactor containment zones with ambient temperatures up to +125°C. IC Role / Device Role / Timing Role: Stable bias source for ionization chamber amplifiers and pulse-height analyzers. Use Value: Operation at +125°C with ≤1 Ω Zdyn prevents gain drift in high-temperature analog signal paths. | Use Scenario: Centigrade thermometers using Kelvin-scale current sources (1 µA/°K) for medical or lab-grade temperature measurement. IC Role / Device Role / Timing Role: Precision voltage reference setting current-source compliance and scaling factor. Use Value: Tight 1.223–1.247 V tolerance directly translates to <±0.1°C absolute accuracy in calibrated thermistor bridges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM185H-1.2-SMD | Same TO-206AA package and 1.2 V nominal output, but rated to MIL-STD-883 Class B (not RHA); no 100 krad(Si) qualification | Approved for military ground systems but not space or high-radiation environments | Select when radiation hardness is unnecessary and cost sensitivity is higher |
| REF102CP | 3-terminal precision reference (VOUT, GND, ADJ); 1.2 V output; ±20 ppm/°C TC; 100 µA min current; SO-8 package | Requires external resistor network for current setting; unsuitable for 2-terminal simplicity or ultra-low-IQ designs | Choose for tighter TC and adjustable output, accepting higher quiescent current and layout complexity |
Compared with LM185H-1.2-SMD, LM185BYH1.2-SMD adds verified 100 krad(Si) radiation tolerance without changing pinout or footprint; versus REF102CP, it eliminates external components and cuts operating current by 10×, at the cost of fixed 2-terminal topology and relaxed TC.
Availability
LM185BYH1.2-SMD is available at Aetrix Electronics and suitable for spacecraft power monitoring, nuclear instrumentation, and portable precision meters requiring stable component supply across extended temperature and radiation environments.
Supply support for LM185BYH1.2-SMD 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, embedded processing, and high-reliability ICs for industrial, aerospace, and automotive markets.
The LM185 family delivers radiation-tolerant, micropower 2-terminal voltage references optimized for space-grade analog subsystems, nuclear instrumentation, and battery-powered metrology equipment.
FAQ
What is the exact reverse breakdown voltage range of LM185BYH1.2-SMD at 10 µA operating current?
The LM185BYH1.2-SMD has a reverse breakdown voltage range of 1.223 V to 1.247 V when operated at 10 µA, as specified in the LM185BY–1.2 Electrical Characteristics table. This 24 mV window reflects factory-trimmed band-gap performance and is guaranteed across −55°C to +125°C ambient temperature.
Does LM185BYH1.2-SMD require external capacitors for stability?
No, LM185BYH1.2-SMD does not require external capacitors for stability. Its internal design provides exceptional tolerance to capacitive loading, allowing direct connection of ≥1 µF bypass capacitors without oscillation-enabling robust filtering in space-constrained or high-noise environments without compensation networks.
Is LM185BYH1.2-SMD pin-compatible with standard TO-206AA (NDU) voltage references?
Yes, LM185BYH1.2-SMD uses the standard TO-206AA (NDU0002A) metal-can package with 2.54 mm lead spacing and axial leads. Its pinout-cathode (notched case side) and anode-is identical to other TO-206AA-packaged references like LM185H-1.2-SMD, enabling direct mechanical and electrical replacement in existing footprints.
What radiation testing standard was used to qualify LM185BYH1.2-SMD for 100 krad(Si)?
LM185BYH1.2-SMD was qualified per MIL-STD-883 Method 1019 (Total Ionizing Dose), with wafer-level testing to 150 krad(Si) to ensure post-100 krad(Si) parameters remain within datasheet limits. Test conditions included low-dose-rate biasing at 10 mrad/s and full electrical characterization before and after irradiation.
Can LM185BYH1.2-SMD operate at −55°C ambient temperature?
Yes, LM185BYH1.2-SMD is fully specified to operate from −55°C to +125°C ambient temperature. Its band-gap core and on-chip trimming maintain reverse breakdown voltage stability and dynamic impedance performance across this full military temperature range, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables.
LM185BYH1.2-SMD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-46-2 Metal Can
- Series:
- -
- Packaging:
- Tray
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.2V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 50ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 10 µA
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-2
LM185BYH1.2-SMD FAQ
1.How can I place an order for LM185BYH1.2-SMD through Aetrix?
Please submit a Request for Quotation (RFQ) for LM185BYH1.2-SMD 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 LM185BYH1.2-SMD reliable?
The price and inventory of LM185BYH1.2-SMD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM185BYH1.2-SMD is usually 5 days.
3.What payment methods are accepted for LM185BYH1.2-SMD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM185BYH1.2-SMD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM185BYH1.2-SMD?
LM185BYH1.2-SMD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM185BYH1.2-SMD 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 LM185BYH1.2-SMD?
For technical support, including LM185BYH1.2-SMD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM185BYH1.2-SMD requirements.
6.How does Aetrix verify that LM185BYH1.2-SMD is sourced from the original manufacturer or authorized distributors?
All LM185BYH1.2-SMD 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 LM185BYH1.2-SMD meets industry standards.
7.What is the process for return or replacement of LM185BYH1.2-SMD?
All LM185BYH1.2-SMD units undergo pre-shipment inspection (PSI). If there is an issue with LM185BYH1.2-SMD, 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 LM185BYH1.2-SMD part is unused and in its original packaging.
Return procedure for LM185BYH1.2-SMD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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