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Texas Instruments LM385BYMX-1.2
- Part No.:
- LM385BYMX-1.2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BYMX-1.2.pdf
- Description:
- IC VREF SHUNT 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,383
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Product details
Overview
LM385BYMX-1.2 from Texas Instruments is a micropower 2-terminal band-gap voltage reference diode delivering a precise 1.235 V output with ±1% initial tolerance, 1 Ω dynamic impedance, and 50 ppm/°C temperature coefficient across 0°C to 70°C. It operates over a 10 μA–20 mA current range and is used in battery-powered precision analog circuits such as portable meters and low-power thermometers.
For engineers reviewing the LM385BYMX-1.2 datasheet, LM385BYMX-1.2 pinout, LM385BYMX-1.2 application, or LM385BYMX-1.2 equivalent, key selection considerations include its SOIC-8 package, 1.235 V reference accuracy, micropower operation down to 10 μA, low noise (60 μVrms), and compatibility with capacitive loads without instability.
Technical Context
The LM385BYMX-1.2 implements a band-gap reference architecture using on-chip trimmed transistors and resistors to achieve stable low-voltage regulation. Its two-terminal configuration simplifies integration into current-source or shunt-reference topologies, and it requires no external components for basic operation.
Designed for the LM385 family's commercial temperature grade (0°C to 70°C), it features tight initial voltage tolerance (±1%), low dynamic impedance (1 Ω at 100 μA), and low wideband noise (60 μVrms, 10 Hz–10 kHz), enabling high-accuracy analog signal conditioning in space- and power-constrained systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal; tight ±1% initial tolerance ensures accurate calibration without post-manufacture trimming. |
| Operating Current Range | 10 μA to 20 mA; supports ultra-low-power sensor interfaces and high-current reference buffering in same device. |
| Dynamic Impedance | 1 Ω at 100 μA; minimizes output voltage shift under load transients, critical for ADC reference stability. |
| Temperature Coefficient | 50 ppm/°C (Y-suffix); limits drift to ±1.75 mV over full 0°C–70°C range, suitable for industrial-grade instrumentation. |
| Wideband Noise | 60 μVrms (10 Hz–10 kHz); enables high-resolution measurements without added filtering in data acquisition systems. |
| Long-Term Stability | 20 ppm over 1000 hours; ensures consistent reference performance in deployed equipment without recalibration. |
Pinout & Package
LM385BYMX-1.2 is housed in an 8-pin SOIC package (Package Drawing D), with pins 1–8 arranged linearly. Pin 1 is the cathode (anode is internally connected to pin 2 via die attach pad). The package includes exposed thermal pad (pin 3) tied to pin 2 or left floating per design requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode | Current sink node; connects to regulated output node in shunt configuration. |
| Pin 2 | Anode | Current source node; ties to supply or ground depending on circuit topology. |
| Pin 3 | Die Attach Pad (DAP) | Internally connected to pin 2; must be soldered to ground plane or left floating-no independent biasing. |
| Pins 4–8 | No Connect (NC) | Unused terminals; electrically isolated and must remain unconnected per TI specification. |
Key Features
| Feature | Design Value |
|---|---|
| ±1% Initial Tolerance | Enables direct use in 12-bit ADC references without calibration, reducing BOM and test cost. |
| 10 μA Minimum Operating Current | Supports operation from coin-cell batteries (e.g., CR2032) with >10-year shelf-life compatible standby current. |
| 1 Ω Dynamic Impedance | Stabilizes reference voltage during fast load steps in precision DAC buffers and sensor excitation circuits. |
| Capacitive Load Tolerance | Operates stably with ≥1 μF output capacitance-eliminates need for isolation resistors in noisy environments. |
| Low 60 μVrms Noise | Preserves SNR in 16-bit+ data converters without requiring external low-noise LDOs or filters. |
Applications
| Portable Multimeter Reference | Micropower Thermometer |
|---|---|
Use Scenario: Handheld digital multimeter requiring stable 1.235 V reference for autoranging ADC and display driver. IC Role / Device Role / Timing Role: Shunt voltage reference providing excitation and scaling for analog front-end and digitization path. Use Value: ±1% tolerance and 50 ppm/°C TC ensure <0.1% full-scale error across operating temperature without firmware compensation. |
Use Scenario: Battery-powered clinical thermometer measuring 0°C–100°C with 0.1°C resolution. IC Role / Device Role / Timing Role: Precision current source driver (via Figure 21) generating 1 μA/K for RTD or thermistor interface. Use Value: 10 μA–20 mA operating range allows programmable current sourcing; low noise avoids digitization jitter in microvolt-level sensing. |
| Low-Voltage Battery Monitor | Calibration Standard for Field Instruments |
Use Scenario: IoT sensor node monitoring 1.5 V alkaline or lithium primary cell voltage over shelf life. IC Role / Device Role / Timing Role: Reference for comparator-based low-battery detection and ADC-based state-of-charge estimation. Use Value: Stable 1.235 V output enables accurate threshold setting down to 1.3 V supply; 20 ppm/1000-hr stability reduces field recalibration frequency. |
Use Scenario: Portable calibration tool verifying accuracy of industrial pressure transmitters and process controllers. IC Role / Device Role / Timing Role: Primary voltage standard in handheld calibrator, driving precision current sources for loop testing. Use Value: 1 Ω dynamic impedance and ±1% tolerance meet ANSI/ISA-51.1 Class C accuracy requirements for field service equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BXMX-1.2/NOPB | ±2% initial tolerance, 150 ppm/°C TC (X-suffix), same SOIC-8 package and 0°C–70°C rating. | Suitable where cost sensitivity outweighs precision; requires tighter system-level calibration. | Select when budget constraints dominate and ±2% reference error is acceptable in final system accuracy budget. |
| LM385M3X-1.2/NOPB | SOT-23-3 package, same ±2% tolerance and 150 ppm/°C TC, but lower thermal resistance (θJA = 283°C/W vs. 165°C/W). | Better suited for space-constrained PCBs; higher thermal impedance may limit max continuous current in high-ambient designs. | Choose for ultra-compact layouts where board area is critical and thermal derating is managed via layout or airflow. |
Compared with LM385BYMX-1.2, LM385BXMX-1.2 trades 1% tolerance for lower unit cost, while LM385M3X-1.2 sacrifices thermal performance and precision for footprint reduction-neither is pin-compatible, requiring layout revision and revalidation.
Availability
LM385BYMX-1.2 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensors, and industrial calibration tools requiring stable component supply with guaranteed long-term continuity.
Supply support for LM385BYMX-1.2 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 expertise in precision reference design and high-reliability manufacturing.
The LM385 series was developed to deliver micropower, high-accuracy shunt references for portable and industrial measurement systems-LM385BYMX-1.2 specifically targets commercial-grade applications needing ±1% tolerance and 50 ppm/°C stability.
FAQ
What is the operating temperature range for LM385BYMX-1.2?
The LM385BYMX-1.2 is rated for operation from 0°C to +70°C, matching the commercial temperature grade of the LM385 family. This range is confirmed in the Absolute Maximum Ratings table and Thermal Characteristics section of the SNVS742E datasheet. Operation outside this range may result in parametric deviation or reliability risk. LM385BYMX-1.2 must not be substituted for military or extended-temperature variants without full system validation.
Does LM385BYMX-1.2 require external capacitors for stability?
No, LM385BYMX-1.2 is explicitly designed to be tolerant of capacitive loading and remains stable with output capacitances up to at least 1 μF, as stated in the FEATURES section of the datasheet. Unlike many older references, it does not require series isolation resistors or minimum ESR constraints. This behavior is inherent to its internal band-gap architecture and has been verified across the full 10 μA–20 mA operating current range.
What is the meaning of the 'Y' suffix in LM385BYMX-1.2?
The 'Y' suffix in LM385BYMX-1.2 denotes a 50 ppm/°C average temperature coefficient, as specified in the Electrical Characteristics table under "Average Temperature Coefficient (5)". This is tighter than the X-suffix (150 ppm/°C) and reflects factory-trimmed performance for higher-precision applications. The 'Y' grade is tested and production-limited-not just a design target-and applies across the full 0°C–70°C operating range.
Can LM385BYMX-1.2 be used as a 3-terminal series reference?
No, LM385BYMX-1.2 is strictly a 2-terminal shunt reference. Its SOIC-8 package contains only two active terminals (pins 1 and 2); pins 4–8 are No Connect, and pin 3 is a die attach pad tied internally to pin 2. It cannot function as a 3-terminal series regulator-it lacks input, output, and ground pins. Attempting series-mode connection violates its electrical architecture and will result in failure or undefined behavior.
How does LM385BYMX-1.2 compare to LM385M3X-1.2/NOPB in terms of thermal performance?
LM385BYMX-1.2 (SOIC-8) has a junction-to-ambient thermal resistance (θJA) of 165°C/W, while LM385M3X-1.2/NOPB (SOT-23) is rated at 283°C/W. This means LM385BYMX-1.2 dissipates heat more effectively-enabling higher continuous current (e.g., 20 mA) at elevated ambient temperatures without exceeding junction limits. For designs operating near 70°C ambient with sustained >10 mA load, LM385BYMX-1.2 provides superior thermal margin and long-term reliability.
LM385BYMX-1.2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 50ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 60µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 15 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM385BYMX-1.2 FAQ
1.How can I place an order for LM385BYMX-1.2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BYMX-1.2 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 LM385BYMX-1.2 reliable?
The price and inventory of LM385BYMX-1.2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385BYMX-1.2 is usually 5 days.
3.What payment methods are accepted for LM385BYMX-1.2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BYMX-1.2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BYMX-1.2?
LM385BYMX-1.2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BYMX-1.2 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 LM385BYMX-1.2?
For technical support, including LM385BYMX-1.2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BYMX-1.2 requirements.
6.How does Aetrix verify that LM385BYMX-1.2 is sourced from the original manufacturer or authorized distributors?
All LM385BYMX-1.2 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 LM385BYMX-1.2 meets industry standards.
7.What is the process for return or replacement of LM385BYMX-1.2?
All LM385BYMX-1.2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BYMX-1.2, 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 LM385BYMX-1.2 part is unused and in its original packaging.
Return procedure for LM385BYMX-1.2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385BYMX-1.2 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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