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Texas Instruments LM385MX-1.2
- Part No.:
- LM385MX-1.2
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM385MX-1.2.pdf
- Description:
- IC VREF SHNT -2.43%/+2.02% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,643
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Product details
Overview
LM385MX-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 operation over 0°C to 70°C. It functions as a low-voltage precision reference in battery-powered analog circuits, portable meters, and micropower regulators.
For engineers reviewing the LM385MX-1.2 datasheet, LM385MX-1.2 pinout, LM385MX-1.2 application, or LM385MX-1.2 equivalent, key selection criteria include its 10 μA–20 mA operating current range, low temperature coefficient (150 ppm/°C), and SOIC-8 package compatibility with surface-mount production workflows.
Technical Context
The LM385MX-1.2 implements a band-gap reference architecture using on-chip trimmed transistors and resistors to achieve stable 1.235 V output across wide current and temperature ranges. Its 2-terminal configuration simplifies integration into current-source or shunt-reference topologies without requiring external biasing circuitry.
Designed for micropower systems, it draws only ~30 μA in typical 9 V battery reference applications and maintains <1.5 mV reverse breakdown voltage change from 10 μA to 1 mA. Its low 1 Ω dynamic impedance ensures minimal load regulation error under varying sink currents.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V nominal; tight tolerance enables direct use in 1.2 V–1.25 V precision analog signal chains without trimming. |
| Initial Tolerance | ±1% at 25°C; reduces calibration overhead in portable instrumentation and sensor front-ends. |
| Operating Current | 10 μA to 20 mA; supports ultra-low-power sleep modes and high-current reference buffering in same device. |
| Dynamic Impedance | 1 Ω at 100 μA; minimizes output voltage shift under transient load changes in ADC reference rails. |
| Temp. Coefficient | 150 ppm/°C (max); ensures ≤1.05 mV drift over full 0°C–70°C industrial range for stable 12-bit accuracy. |
| Long-Term Stability | 20 ppm over 1000 hours; critical for unattended field-deployed sensors requiring minimal recalibration. |
Pinout & Package
LM385MX-1.2 is packaged in an 8-pin SOIC (Package Drawing D) with standard pinout per TI's LM385 family. Pin 1 is the cathode (reference output), Pin 2 is the anode (current input), and Pins 3–8 are NC or die attach pad connections - consistent with Figure 3 of SNVS742E.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode | Reference voltage output node; connects to load or feedback network in shunt configuration. |
| Pin 2 | Anode | Current input terminal; sinks regulated current from supply through series resistor. |
| Pins 3–8 | No Connect / Die Attach Pad | Internally tied to substrate; must be left floating or connected to Pin 2 per TI recommendation to avoid parasitic leakage. |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive Load Tolerance | Stable with ≥1 μF output capacitance; eliminates need for external compensation in battery-monitoring circuits. |
| Low Operating Current | Functional down to 10 μA; enables multi-year operation from coin cells in IoT endpoint sensors. |
| Wide Dynamic Range | Regulates accurately from 10 μA to 20 mA; allows reuse across low-power sensing and higher-current DAC reference designs. |
| On-Chip Trimming | Factory-trimmed to ±1% tolerance; removes manual potentiometer adjustment in production test fixtures. |
Applications
| Portable Battery-Powered Meters | Micropower Voltage Regulators |
|---|---|
Use Scenario: Handheld multimeters and pH meters powered by 9 V alkaline batteries requiring stable reference for 12-bit ADCs. IC Role / Device Role / Timing Role: Shunt voltage reference providing 1.235 V基准 for ADC internal reference buffer and analog front-end gain calibration. Use Value: Enables >10,000 readings per battery with <0.5 LSB reference drift over shelf life due to 20 ppm/1000 hr stability. | Use Scenario: Low-quiescent linear regulators for wearable health monitors where standby current must stay below 50 μA. IC Role / Device Role / Timing Role: Precision current source controlling pass transistor base/gate to generate regulated 3.3 V or 5 V output. Use Value: Achieves IQ ≃30 μA system standby while maintaining ±0.5% output accuracy across temperature via 1 Ω dynamic impedance. |
| 0°C–100°C Thermometers | Micropower Thermocouple Compensators |
Use Scenario: Digital thermometers using platinum RTD or thermistor bridges with Kelvin-based linearization. IC Role / Device Role / Timing Role: Fixed 1.235 V reference establishing 1 μA/°K current source for direct centigrade-to-voltage conversion. Use Value: Delivers ±0.2°C accuracy over full range without external op-amps, leveraging tight 150 ppm/°C TC and low noise. | Use Scenario: Cold-junction compensation in industrial K-type thermocouple interfaces with 50 μA total supply budget. IC Role / Device Role / Timing Role: Precision 1.235 V reference setting thermocouple amplifier gain and offset to match Seebeck coefficient (40.8 μV/°C). Use Value: Maintains <1°C measurement error over 0°C–70°C ambient by tracking thermocouple cold-junction drift with matched TC. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BZ-1.2/NOPB | TO-92 package, 3-pin, 0°C–70°C rating, same ±1% tolerance and 1.235 V output. | Suitable for through-hole prototyping or space-constrained PCBs where SOIC footprint is unavailable. | Select when manual assembly, thermal mass requirements, or legacy board layouts favor axial leaded packages. |
| LM385M3X-1.2/NOPB | SOT-23-3 package, 3-pin, identical electrical specs but smaller footprint and lower thermal resistance (170°C/W vs 165°C/W). | Ideal for ultra-dense wearables or medical patches where board area is limited to <2 mm² per component. | Choose for highest density designs where reflow compatibility and 1.12 mm max height are mandatory. |
Compared with LM385BZ-1.2/NOPB and LM385M3X-1.2/NOPB, the LM385MX-1.2 offers superior manufacturability in automated SMT lines via SOIC-8 tape-and-reel delivery (2500 pcs/reel), balanced thermal performance, and proven long-term stability in volume production.
Availability
LM385MX-1.2 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensors, and industrial temperature monitoring requiring stable component supply and RoHS-compliant packaging.
Supply support for LM385MX-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 analog ICs and voltage references.
The LM385 series was designed specifically for micropower, low-voltage reference applications in battery-operated equipment-emphasizing ultra-low current operation, tight initial tolerance, and robust capacitive-load stability.
FAQ
What is the exact reference voltage output of LM385MX-1.2 at 25°C?
The LM385MX-1.2 delivers a nominal 1.235 V reference voltage at 25°C, with ±1% initial tolerance (1.223 V to 1.247 V). This value is factory-trimmed and specified under 10 μA ≤ IR ≤ 20 mA conditions per SNVS742E Electrical Characteristics table.
Can LM385MX-1.2 operate from a 1.5 V battery?
Yes - the LM385MX-1.2 can function as a shunt reference from a 1.5 V battery when used with appropriate series resistance. Figure 16 in SNVS742E demonstrates this configuration, achieving stable 1.235 V output with ~20 μA quiescent current and no external active components.
What is the maximum operating temperature range for LM385MX-1.2?
The LM385MX-1.2 is rated for operation from 0°C to +70°C, as confirmed in the Absolute Maximum Ratings table and Package Option Addendum. This distinguishes it from the LM285-1.2-N (−40°C to +85°C) and LM185-1.2-N (−55°C to +125°C) variants.
Does LM385MX-1.2 require external capacitors for stability?
No - the LM385MX-1.2 is explicitly designed to be exceptionally tolerant of capacitive loading, remaining stable with ≥1 μF output capacitance. This eliminates the need for external compensation capacitors in most applications, including those with long PCB traces or EMI-filtering caps.
Is LM385MX-1.2 pin-compatible with other LM385-1.2 variants in SOIC-8?
Yes - all LM385-1.2 variants in SOIC-8 (e.g., LM385BMX-1.2/NOPB, LM385BXMX-1.2/NOPB) share identical pinout, package drawing (D), and mechanical dimensions. The LM385MX-1.2 differs only in grade (standard grade, not B- or X-grade) and marking, but maintains full functional and layout compatibility.
LM385MX-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:
- -2.43%, +2.02%
- 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
LM385MX-1.2 FAQ
1.How can I place an order for LM385MX-1.2 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385MX-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 LM385MX-1.2 reliable?
The price and inventory of LM385MX-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 LM385MX-1.2 is usually 5 days.
3.What payment methods are accepted for LM385MX-1.2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385MX-1.2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385MX-1.2?
LM385MX-1.2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385MX-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 LM385MX-1.2?
For technical support, including LM385MX-1.2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385MX-1.2 requirements.
6.How does Aetrix verify that LM385MX-1.2 is sourced from the original manufacturer or authorized distributors?
All LM385MX-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 LM385MX-1.2 meets industry standards.
7.What is the process for return or replacement of LM385MX-1.2?
All LM385MX-1.2 units undergo pre-shipment inspection (PSI). If there is an issue with LM385MX-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 LM385MX-1.2 part is unused and in its original packaging.
Return procedure for LM385MX-1.2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385MX-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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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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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
Diodes Incorporated
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