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Texas Instruments LM385BMX-1.2
- Part No.:
- LM385BMX-1.2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385BMX-1.2.pdf
- Description:
- IC VREF SHUNT 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,256
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Product details
Overview
LM385BMX-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 across 0°C to 70°C. It operates over a 10 μA–20 mA current range and enables ultra-low-power analog circuitry such as portable meters and battery-powered thermometers.
For engineers reviewing the LM385BMX-1.2 datasheet, LM385BMX-1.2 pinout, LM385BMX-1.2 application, or LM385BMX-1.2 equivalent, key selection criteria include its SOIC-8 package, tight initial voltage accuracy, low dynamic impedance for stable regulation under varying load, and compatibility with micropower current sources and precision sensor biasing circuits.
Technical Context
The LM385BMX-1.2 implements a band-gap reference architecture using on-chip trimmed transistors and resistors to achieve low noise (60 μVrms, 10 Hz–10 kHz), excellent long-term stability (20 ppm/1000 hr), and robust capacitive loading tolerance. Its 2-terminal configuration simplifies integration into compact, low-component-count designs.
Rated for 0°C to 70°C operation, it supports wide-range current sourcing (10 μA–20 mA) without external components, enabling direct use in 1.5 V battery references, 5 V regulators, and precision current sources - all while maintaining sub-20 mV voltage change across its full operating current range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal; ensures accurate biasing and calibration in low-voltage sensor interfaces and ADC references. |
| Initial Tolerance | ±1% at 25°C; eliminates need for post-assembly trimming in production-grade portable instrumentation. |
| Operating Current Range | 10 μA to 20 mA; supports both ultra-low-power standby modes and higher-current regulator feedback paths. |
| Dynamic Impedance | 1 Ω at 100 μA; maintains stable output voltage despite rapid load transients in precision analog signal chains. |
| Temperature Coefficient | 30 ppm/°C (X suffix); guarantees ≤0.9 mV drift over full 0°C–70°C industrial range for reliable field operation. |
| Long-Term Stability | 20 ppm/1000 hr; minimizes calibration drift in battery-powered devices requiring multi-year operational integrity. |
Pinout & Package
LM385BMX-1.2 is housed in an 8-pin SOIC (Package Drawing D) with standard JEDEC MS-012, AA variant footprint. The device uses a 2-terminal configuration: Pin 1 is Cathode, Pin 2 is Anode; Pins 3–8 are NC (no connection) and internally unconnected.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode | Reference output node; connects to regulated load or feedback network; requires no external capacitor for stability. |
| Pin 2 | Anode | Current input terminal; ties to supply rail or current source; reverse-biased operation establishes reference voltage. |
| Pins 3–8 | No Connection | Internally isolated; must remain unconnected per TI design; no thermal or electrical function. |
Key Features
| Feature | Design Value |
|---|---|
| Micropower Operation | Functional down to 10 μA supply current - enables >10-year battery life in 9 V-powered handheld calibrators. |
| Capacitive Load Tolerance | Stable with unlimited output capacitance - eliminates need for series isolation resistors in noisy environments. |
| Low Wideband Noise | 60 μVrms (10 Hz–10 kHz) - preserves SNR in high-resolution ADC front-ends and precision DAC references. |
| On-Chip Trimmed Accuracy | ±1% initial tolerance achieved via laser trimming - reduces BOM count and eliminates manual potentiometer adjustment. |
| Hermetic Stability | 20 ppm/1000 hr long-term drift - ensures repeatable calibration in field-deployed environmental sensors. |
Applications
| Portable Battery-Powered Meters | Precision Temperature Sensing |
|---|---|
Use Scenario: Handheld multimeters and pH meters powered by single 9 V or dual 1.5 V alkaline cells. IC Role / Device Role / Timing Role: 2-terminal voltage reference providing stable 1.235 V reference for ADC conversion and display driver biasing. Use Value: Enables >5-year shelf-life-compatible operation with <30 μA total system quiescent current and ±0.5% measurement accuracy. |
Use Scenario: Digital thermometer modules measuring 0°C–100°C using thermistor or RTD bridges. IC Role / Device Role / Timing Role: Precision bias source for Wheatstone bridge excitation and ratiometric ADC reference. Use Value: Delivers <1 mV total error over temperature due to 30 ppm/°C TC and 1 Ω dynamic impedance. |
| Micropower Current Sources | Low-Voltage Regulator Reference |
Use Scenario: 1 μA–1 mA programmable current sources for gas sensor biasing and photodiode TIA feedback. IC Role / Device Role / Timing Role: Stable voltage reference setting current through external sense resistor in emitter-follower or op-amp topology. Use Value: Maintains ±0.2% current accuracy across 10 μA–20 mA operating range with no external compensation. |
Use Scenario: 5 V linear regulator feedback network in space-constrained IoT nodes powered from 9 V batteries. IC Role / Device Role / Timing Role: High-accuracy reference input to TL431 or discrete op-amp error amplifier. Use Value: Improves output regulation to ±0.8% vs. ±2.5% using standard zener diodes, extending usable battery voltage range. |
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 | Same SOIC-8 package, ±2% initial tolerance, 50 ppm/°C TC (Y suffix) | Lower accuracy; suitable for non-critical biasing where cost is prioritized over precision | Select when ±2% reference error is acceptable and long-term drift budget allows 50 ppm/°C |
| LM385M3X-1.2/NOPB | SOT-23-3 package, same ±1% tolerance, identical electrical specs, 1.12 mm max height | Space-constrained PCBs requiring footprint reduction without sacrificing accuracy or stability | Choose for ultra-dense layouts where SOIC-8 real estate is unavailable but 1.235 V precision remains mandatory |
Compared with LM385BMX-1.2, LM385BXMX-1.2/NOPB trades initial accuracy and temperature stability for lower unit cost, while LM385M3X-1.2/NOPB delivers identical performance in a 60% smaller footprint - making the latter ideal for wearables and miniaturized sensor nodes where board area is critical.
Availability
LM385BMX-1.2 is available at Aetrix Electronics and suitable for portable instrumentation, precision sensor interfaces, and micropower regulator designs requiring stable component supply, RoHS-compliant packaging, and guaranteed long-term availability.
Supply support for LM385BMX-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 family was engineered specifically for micropower, high-stability voltage referencing in battery-operated and portable measurement systems - emphasizing low drift, wide current range, and ease of use in minimal-component circuits.
FAQ
What is the operating temperature range for LM385BMX-1.2?
The LM385BMX-1.2 is rated for operation from 0°C to +70°C. This industrial-grade range supports deployment in commercial and light-industrial environments such as handheld test equipment and environmental monitoring nodes. It does not support extended temperature grades like −40°C to +85°C (LM285) or −55°C to +125°C (LM185).
Does LM385BMX-1.2 require an external capacitor for stability?
No, LM385BMX-1.2 is explicitly designed to be stable with unlimited capacitive loading - a key feature confirmed in the TI datasheet. Unlike many shunt references, it does not require series resistance or output capacitors, simplifying layout and improving reliability in high-noise or vibration-prone applications.
What is the maximum reverse current rating for LM385BMX-1.2?
The absolute maximum reverse current for LM385BMX-1.2 is 30 mA. However, its specified operating range is 10 μA to 20 mA, and performance parameters (e.g., voltage accuracy, dynamic impedance) are guaranteed only within that range. Exceeding 20 mA may increase self-heating and degrade long-term stability.
How does the LM385BMX-1.2 differ from the LM385M-1.2/NOPB?
LM385BMX-1.2 features ±1% initial tolerance and 30 ppm/°C temperature coefficient (X suffix), whereas LM385M-1.2/NOPB has ±2% tolerance and 50 ppm/°C TC (Y suffix). Both share the same SOIC-8 package and 0°C–70°C rating, but LM385BMX-1.2 delivers tighter accuracy for metrology-grade applications.
Can LM385BMX-1.2 be used as a 1.2 V reference in a 1.5 V battery-powered circuit?
Yes - LM385BMX-1.2 is routinely used in 1.5 V battery applications (e.g., Figure 16 in the datasheet). With a minimum operating current of 10 μA and 1.235 V breakdown, it draws negligible current from the cell while maintaining regulation, enabling stable operation until battery voltage drops below ~1.3 V.
LM385BMX-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:
- 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
LM385BMX-1.2 FAQ
1.How can I place an order for LM385BMX-1.2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385BMX-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 LM385BMX-1.2 reliable?
The price and inventory of LM385BMX-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 LM385BMX-1.2 is usually 5 days.
3.What payment methods are accepted for LM385BMX-1.2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385BMX-1.2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385BMX-1.2?
LM385BMX-1.2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385BMX-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 LM385BMX-1.2?
For technical support, including LM385BMX-1.2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385BMX-1.2 requirements.
6.How does Aetrix verify that LM385BMX-1.2 is sourced from the original manufacturer or authorized distributors?
All LM385BMX-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 LM385BMX-1.2 meets industry standards.
7.What is the process for return or replacement of LM385BMX-1.2?
All LM385BMX-1.2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385BMX-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 LM385BMX-1.2 part is unused and in its original packaging.
Return procedure for LM385BMX-1.2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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