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Texas Instruments LM385M3-2.5
- Part No.:
- LM385M3-2.5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
LM385M3-2.5.pdf
- Description:
- IC VREF SHUNT 3% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,350
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Product details
Overview
LM385M3-2.5 from Texas Instruments is a micropower 2-terminal band-gap voltage reference delivering a precise 2.5 V output with ±20 mV (±0.8%) initial tolerance, 0.6 Ω dynamic impedance (A grade), and operation over 20 μA to 20 mA supply current across 0°C to 70°C. It serves as a stable reference in portable meters, battery-powered analog circuits, and precision current sources.
For engineers reviewing the LM385M3-2.5 datasheet, LM385M3-2.5 pinout, LM385M3-2.5 application, or LM385M3-2.5 equivalent, key selection criteria include its SOT-23 package, low temperature coefficient (≤150 ppm/°C), wide operating current range, capacitive loading tolerance, and suitability for micropower systems requiring long battery life.
Technical Context
The LM385M3-2.5 implements a two-terminal band-gap architecture using only transistors and resistors, enabling low noise, excellent long-term stability (20 ppm after 1000 hours), and minimal sensitivity to capacitive loading. Its internal trimming ensures tight initial voltage accuracy without external calibration.
It operates as a shunt reference: reverse-biased across a current source, regulating voltage by sinking variable current while maintaining 2.5 V across its terminals. The device exhibits low dynamic impedance (0.6 Ω at 100 μA, f = 20 Hz) and wideband noise of 120 μVrms (10 Hz–10 kHz), supporting high-precision ADC/DAC biasing and sensor excitation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.500 V ±20 mV (±0.8%) - ensures accurate scaling in 12-bit+ data converters and calibrated measurement front-ends |
| Operating Current Range | 20 μA to 20 mA - supports ultra-low-power sleep modes and higher-drive applications without redesign |
| Dynamic Impedance | 0.6 Ω (A grade, IR = 100 μA, f = 20 Hz) - minimizes output voltage shift under load transients |
| Temperature Coefficient | ≤150 ppm/°C (max) - limits drift to <±1.75 mV over full 0°C–70°C range |
| Wideband Noise | 120 μVrms (10 Hz–10 kHz) - preserves signal integrity in low-noise amplifiers and precision instrumentation |
| Long-Term Stability | 20 ppm (1000 hr, TA = 25°C) - reduces recalibration frequency in field-deployed equipment |
Pinout & Package
SOT-23 package (DBZ drawing), 3-pin surface-mount, 1.12 mm max height, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Current sink input | Connects to regulated output node; sinks all operating current |
| Cathode (Pin 2) | Reference voltage output | Provides stable 2.5 V; must be decoupled locally for noise rejection |
| NC / Die Attach Pad (Pin 3) | Thermal pad / mechanical anchor | Internally connected to die substrate; recommended to connect to cathode (Pin 2) for thermal and noise performance |
Key Features
| Feature | Design Value |
|---|---|
| Capacitive loading tolerance | Stable with ≥10 μF ceramic output capacitance - eliminates need for series resistance in battery-powered designs |
| Micropower operation | 20 μA minimum operating current - enables multi-year battery life in IoT sensors and portable meters |
| Low dynamic impedance | 0.6 Ω at 100 μA - maintains regulation during fast current steps in DAC reference buffers |
| Hermetic-grade stability | 20 ppm long-term drift (1000 hr) - meets industrial calibration interval requirements without active compensation |
| Shunt topology | Two-terminal configuration - simplifies PCB layout vs. three-terminal references; requires only one external resistor |
Applications
| Portable Digital Multimeter | Wireless Sensor Node ADC Reference |
|---|---|
Use Scenario: Battery-powered handheld DMM requiring stable 2.5 V reference for 16-bit SAR ADC and auto-ranging circuitry. IC Role / Device Role / Timing Role: Shunt voltage reference providing excitation and scaling reference for analog front-end and ADC. Use Value: 20 μA minimum operating current extends alkaline battery life beyond 2 years; ±20 mV initial tolerance enables factory calibration without trimming. | Use Scenario: Sub-100 μA wireless temperature node using a low-power MCU and sigma-delta ADC. IC Role / Device Role / Timing Role: Precision 2.5 V reference for ratiometric sensor excitation and ADC reference voltage. Use Value: 0.6 Ω dynamic impedance prevents reference droop during ADC sampling bursts; capacitive loading tolerance allows direct connection to 4.7 μF ceramic bulk cap. |
| Calibrated Thermocouple Interface | Micropower Current Source |
Use Scenario: Industrial thermocouple transmitter with cold-junction compensation and 4–20 mA loop output. IC Role / Device Role / Timing Role: Stable 2.5 V reference for precision op-amp gain-setting and thermocouple amplifier offset correction. Use Value: ≤150 ppm/°C tempco ensures <±0.5°C error contribution over 0°C–70°C ambient; low noise avoids corruption of microvolt-level thermocouple signals. | Use Scenario: Programmable 1–100 μA current source for photodiode biasing in optical smoke detectors. IC Role / Device Role / Timing Role: Reference element in Howland current source topology, setting compliance voltage and gain. Use Value: Tight ±20 mV tolerance directly translates to <±0.8% current accuracy; 20 mA max current supports high-side sensing configurations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM385BZ-2.5/NOPB | TO-92 package (3-pin), same electrical specs, 0°C–70°C rating, higher thermal resistance (θJA = 440°C/W) | Through-hole assembly; less suitable for space-constrained PCBs or automated SMT lines | Select when manual assembly, prototyping, or legacy through-hole compatibility is required |
| REF3025AIDBZR | 3-pin SOT-23, 2.5 V, ±0.2% initial accuracy, 50 ppm/°C max tempco, 50 μA typical quiescent current | Higher accuracy and lower tempco, but higher minimum current and different pinout (VOUT, GND, IN) | Select when tighter initial tolerance and temperature stability are critical, and board layout allows 3-pin configuration |
Compared with LM385BZ-2.5/NOPB, the LM385M3-2.5 offers superior thermal performance in SMT layouts and smaller footprint; compared with REF3025AIDBZR, it delivers lower quiescent current and simpler 2-terminal interface at the cost of relaxed initial tolerance and tempco.
Availability
LM385M3-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, wireless sensor nodes, and calibrated industrial interfaces requiring stable component supply, consistent parametric performance, and long-lifecycle availability.
Supply support for LM385M3-2.5 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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs and power management solutions.
The LM385 series belongs to TI's precision voltage reference product line, designed specifically for micropower, low-drift, and high-stability applications in battery-operated and industrial measurement systems.
FAQ
What is the operating temperature range for the LM385M3-2.5?
The LM385M3-2.5 is rated for operation from 0°C to 70°C. This commercial-grade temperature range aligns with its intended use in consumer electronics, portable instruments, and non-military industrial environments. It is distinct from the wider-range LM285-2.5-N (−40°C to +85°C) and LM185-2.5-N (−55°C to +125°C) variants.
How does the LM385M3-2.5 differ from the LM385MX-2.5/NOPB?
The LM385M3-2.5 uses a 3-pin SOT-23 (DBZ) package, whereas the LM385MX-2.5/NOPB uses an 8-pin SOIC (D) package. Both share identical electrical specifications, temperature range (0°C–70°C), and marking "LM385 M2.5", but differ in footprint, thermal resistance (SOT-23 θJA = 440°C/W vs. SOIC θJA = 165°C/W), and assembly process compatibility.
Can the LM385M3-2.5 be used with large output capacitors?
Yes - the LM385M3-2.5 is explicitly designed for exceptional capacitive loading tolerance, remaining stable with ≥10 μF ceramic output capacitance. This eliminates the need for series isolation resistors commonly required with other shunt references, simplifying design in battery-powered systems where bulk capacitance is used for transient load support.
What is the minimum operating current for the LM385M3-2.5?
The LM385M3-2.5 has a minimum operating current of 20 μA, verified per the Electrical Characteristics table in the SNVS743D datasheet. Below this threshold, regulation is not guaranteed; operation at 20 μA enables ultra-low-power applications such as multidecade sleep-mode sensors and energy-harvesting systems.
Is Pin 3 of the LM385M3-2.5 electrically functional or just a thermal pad?
Pin 3 of the LM385M3-2.5 is the die attach pad (DAP), internally connected to the silicon substrate. It is not an active signal terminal but serves thermal and mechanical functions. TI recommends connecting it to the cathode (Pin 2) to improve thermal dissipation and reduce noise coupling - a practice confirmed in the DBZ package documentation and application notes.
LM385M3-2.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±3%
- Temperature Coefficient:
- 150ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 120µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 15 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
LM385M3-2.5 FAQ
1.How can I place an order for LM385M3-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM385M3-2.5 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 LM385M3-2.5 reliable?
The price and inventory of LM385M3-2.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM385M3-2.5 is usually 5 days.
3.What payment methods are accepted for LM385M3-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM385M3-2.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM385M3-2.5?
LM385M3-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM385M3-2.5 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 LM385M3-2.5?
For technical support, including LM385M3-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM385M3-2.5 requirements.
6.How does Aetrix verify that LM385M3-2.5 is sourced from the original manufacturer or authorized distributors?
All LM385M3-2.5 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 LM385M3-2.5 meets industry standards.
7.What is the process for return or replacement of LM385M3-2.5?
All LM385M3-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM385M3-2.5, 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 LM385M3-2.5 part is unused and in its original packaging.
Return procedure for LM385M3-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM385M3-2.5 Tags
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