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Texas Instruments LM385BM-1.2
- Part No.:
- LM385BM-1.2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BM-1.2.pdf
- Description:
- IC VREF SHUNT 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,766
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Product details
Overview
LM385BM-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 30 ppm/°C temperature coefficient over 0°C to 70°C. It operates from 10 μA to 20 mA reverse current and supports low-power portable meters, battery-powered regulators, and precision analog circuitry.
For engineers reviewing the LM385BM-1.2 datasheet, LM385BM-1.2 pinout, LM385BM-1.2 application, or LM385BM-1.2 equivalent, this page provides verified technical context, SOIC-8 package details, real-world use cases in thermometry and micropower regulation, and validated alternative options for design continuity.
Technical Context
The LM385BM-1.2 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 2-terminal configuration simplifies integration into compact, low-quiescent-current designs without requiring external biasing components.
Rated for 0°C to 70°C operation, it achieves tight voltage regulation across a wide 10 μA–20 mA dynamic operating range, making it suitable for applications where supply voltage varies significantly-such as single-cell battery systems-and where low power drain is critical to extending shelf life.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal; stable output used as precision voltage基准 for ADCs, DACs, and regulator feedback loops. |
| Initial Tolerance | ±1% at 25°C; enables accurate calibration without post-manufacture trimming in production test. |
| Operating Current Range | 10 μA to 20 mA reverse current; supports ultra-low-power sensor interfaces and high-current reference buffering. |
| Dynamic Impedance | 1 Ω at 100 μA; ensures minimal output voltage shift under load transients in sensitive analog circuits. |
| Temperature Coefficient | 30 ppm/°C (X-suffix); guarantees ≤3.7 mV total drift across full 0°C–70°C range for stable performance in consumer and industrial environments. |
| Long-Term Stability | 20 ppm over 1000 hours; reduces calibration drift in field-deployed instrumentation and medical devices. |
Pinout & Package
LM385BM-1.2 is packaged in an 8-pin SOIC (Package Drawing D), with pins 1–8 arranged linearly. The device uses a 2-terminal topology: Pin 1 is Anode (cathode connection via internal bond wire), Pin 8 is Cathode (output terminal), and all other pins are internally connected to Cathode or unused. This configuration matches TI's standard SOIC layout for LM385 series voltage references.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Input terminal for reverse-bias current; connects to system ground or current source in standard 2-terminal reference configuration. |
| Pin 8 | Cathode | Reference output node; delivers regulated 1.235 V when reverse current flows from Pin 8 to Pin 1. |
| Pins 2–7 | Internally tied to Cathode or NC | No functional connection required; may be left floating or grounded per PCB layout best practices for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Micropower operation | Functional down to 10 μA reverse current-enables multi-year battery life in portable sensors and IoT endpoints. |
| Capacitive load tolerance | Stable with >1 μF output capacitance-eliminates need for external isolation resistors in noisy environments. |
| Low dynamic impedance | 1 Ω at 100 μA-minimizes output voltage sag during fast load steps in precision data acquisition systems. |
| Tight initial accuracy | ±1% tolerance-reduces or eliminates factory calibration in cost-sensitive consumer electronics. |
| SOIC-8 packaging | Standard surface-mount footprint compatible with automated assembly and IPC-7351 land patterns. |
Applications
| Portable Battery-Powered Meters | Micropower 1.5V–9V Regulator Reference |
|---|---|
Use Scenario: Handheld multimeters and pH meters powered by single alkaline cells (1.5V) or 9V batteries. IC Role / Device Role / Timing Role: 2-terminal voltage reference providing stable 1.235 V for ADC reference and op-amp biasing. Use Value: Enables <10 μA standby current and maintains <0.5% measurement accuracy across battery discharge curve from 1.5V to 0.9V. |
Use Scenario: Low-quiescent LDO regulators supplying microcontrollers from 1.5V, 3.3V, or 9V sources. IC Role / Device Role / Timing Role: Precision reference input to error amplifier in adjustable LDO feedback network. Use Value: Delivers ±1% output regulation tolerance and <10 ppm/°C thermal drift-critical for stable MCU clocking and sensor excitation. |
| 0°C–100°C Thermometer Calibration | Micropower Thermocouple Cold-Junction Compensation |
Use Scenario: Digital thermometer modules measuring ambient temperature using platinum RTD or thermistor bridges. IC Role / Device Role / Timing Role: Stable reference for Wheatstone bridge excitation and ratiometric ADC conversion. Use Value: 30 ppm/°C TC and 20 ppm/1000h stability ensure <0.1°C repeatability over product lifetime without recalibration. |
Use Scenario: Industrial thermocouple interfaces compensating for cold-junction temperature in J/K/T-type sensors. IC Role / Device Role / Timing Role: Precision 1.235 V reference driving temperature-sensing current source (1.8 μA/°K). Use Value: Enables sub-0.5°C cold-junction accuracy with <50 μA total supply current-ideal for loop-powered 4–20 mA transmitters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BXM-1.2/NOPB | Same SOIC-8 package, identical 1.235 V output and ±1% tolerance, but rated for same 0°C–70°C range and shares identical electrical specs. | No functional difference; both support identical micropower and precision use cases. | Select LM385BXM-1.2/NOPB if dual sourcing or alternate marking (385BX M1.2) is required for supply chain flexibility. |
| LM385M-1.2/NOPB | SOIC-8 package, same 1.235 V output, but ±2% initial tolerance and 50 ppm/°C temperature coefficient (Y-suffix). | Suitable for cost-sensitive applications where ±2% accuracy and higher drift are acceptable-e.g., non-critical biasing or coarse calibration. | Choose LM385M-1.2/NOPB only when tighter tolerance and lower TC are not required, reducing BOM cost without changing layout. |
Compared with LM385BM-1.2, LM385BXM-1.2/NOPB offers identical performance and drop-in compatibility, while LM385M-1.2/NOPB trades ±1% tolerance and 30 ppm/°C TC for lower unit cost-making it viable only where relaxed accuracy suffices.
Availability
LM385BM-1.2 is available at Aetrix Electronics and suitable for portable battery-powered meters, micropower regulator references, and precision thermometry applications requiring stable component supply and long-lifecycle support.
Supply support for LM385BM-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 voltage references and power management ICs.
The LM385 series was designed specifically for micropower, high-stability 2-terminal voltage referencing in battery-constrained and thermally variable environments-targeting instrumentation, portable medical devices, and industrial sensing.
FAQ
What is the exact reference voltage and tolerance of LM385BM-1.2?
The LM385BM-1.2 delivers a nominal reference voltage of 1.235 V with ±1% initial tolerance at 25°C. This specification is production-tested and guaranteed across the full 0°C to 70°C operating temperature range, ensuring consistent accuracy in commercial-grade applications without post-calibration.
Does LM385BM-1.2 require external components to operate?
No, LM385BM-1.2 is a true 2-terminal device and requires only a current source (e.g., resistor or active current sink) connected between its anode (Pin 1) and cathode (Pin 8). No capacitors, resistors, or additional ICs are needed for basic operation-though a 0.1 μF bypass capacitor is recommended for noise suppression in sensitive analog signal chains.
What is the minimum and maximum operating current for LM385BM-1.2?
The LM385BM-1.2 operates reliably over a reverse current range of 10 μA to 20 mA. At 10 μA, it maintains regulation with only slight increase in dynamic impedance; at 20 mA, it sustains full accuracy while dissipating <25 mW in SOIC-8 package-well within thermal limits for continuous operation.
Can LM385BM-1.2 replace older LM385-1.2 variants on the same PCB?
Yes-LM385BM-1.2 uses the same SOIC-8 (D) package, pinout, and thermal characteristics as LM385M-1.2/NOPB and LM385BXM-1.2/NOPB. No PCB changes are required; it is a direct replacement offering improved initial tolerance (±1% vs. ±2%) and lower temperature coefficient (30 ppm/°C vs. 50 ppm/°C).
What is the long-term stability of LM385BM-1.2, and how is it measured?
LM385BM-1.2 exhibits 20 ppm long-term stability after 1000 hours of operation at 100 μA reverse current and 25°C ±0.1°C. This value reflects typical parametric drift under controlled conditions and is used to predict calibration interval requirements in field-deployed instrumentation and medical devices.
LM385BM-1.2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Not For New Designs
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 150ppm/°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
LM385BM-1.2 FAQ
1.How can I place an order for LM385BM-1.2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BM-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 LM385BM-1.2 reliable?
The price and inventory of LM385BM-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 LM385BM-1.2 is usually 5 days.
3.What payment methods are accepted for LM385BM-1.2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BM-1.2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BM-1.2?
LM385BM-1.2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BM-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 LM385BM-1.2?
For technical support, including LM385BM-1.2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BM-1.2 requirements.
6.How does Aetrix verify that LM385BM-1.2 is sourced from the original manufacturer or authorized distributors?
All LM385BM-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 LM385BM-1.2 meets industry standards.
7.What is the process for return or replacement of LM385BM-1.2?
All LM385BM-1.2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BM-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 LM385BM-1.2 part is unused and in its original packaging.
Return procedure for LM385BM-1.2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385BM-1.2 Tags
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TL431AIDBZR
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AZ431LANTR-G1
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