Texas Instruments LM385M3X-2.5/NOPB

Overview

LM385M3X-2.5/NOPB 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, 30 ppm/°C average temperature coefficient, and 0.6 Ω dynamic impedance. It operates over 20 μA to 20 mA supply current and is rated for 0°C to 70°C ambient, making it suitable for battery-powered precision analog circuits including portable meters and sensor signal conditioning.

For engineers reviewing the LM385M3X-2.5/NOPB datasheet, LM385M3X-2.5/NOPB pinout, LM385M3X-2.5/NOPB application, or LM385M3X-2.5/NOPB equivalent, key selection criteria include its SOT-23 package compatibility, low 20 μA minimum operating current, tight 2.5 V reference stability across temperature and load, and suitability for space-constrained micropower designs requiring long battery life.

Technical Context

The LM385M3X-2.5/NOPB uses a band-gap core with on-chip trimming to achieve tight initial voltage accuracy and low drift. Its 2-terminal architecture simplifies integration into current-source or shunt-reference configurations without external biasing components.

Designed for wide-current operation (20 μA–20 mA), it maintains stable regulation across varying supply conditions and exhibits exceptionally low dynamic impedance (0.6 Ω at 100 μA), enabling effective noise suppression in high-precision ADC references and low-power sensor interfaces.

Key Specifications

Pinout & Package

SOT-23 (DBZ) 3-pin surface-mount package with 1.12 mm max height, JEDEC TO-236 compliant. Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Die Attach Pad (DAP), electrically connected to Pin 2 per TI documentation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage reference applications.

Compared with LM385M3-2.5/NOPB, the LM385M3X-2.5/NOPB delivers tighter initial accuracy and lower temperature drift at identical current consumption and footprint; versus REF3025AIDBZR, it trades lower quiescent current and smaller size for modestly higher noise and drift-ideal for cost-optimized, space-constrained micropower systems.

Availability

LM385M3X-2.5/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensor nodes, and handheld test equipment requiring stable component supply with guaranteed long-term continuity.

Supply support for LM385M3X-2.5/NOPB 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 leadership in precision analog ICs and voltage references.

The LM385 series was designed for micropower, high-stability shunt references in portable and space-constrained applications-emphasizing low IQ, robust capacitive loading behavior, and long-term reliability without external components.

FAQ

What is the maximum reverse current rating for LM385M3X-2.5/NOPB?

The absolute maximum reverse current for LM385M3X-2.5/NOPB is 30 mA, as specified in the TI datasheet SNVS743D. Exceeding this limit risks permanent damage. For reliable operation, maintain reverse current within the recommended 20 μA to 20 mA range, where the device delivers its specified 2.5 V reference accuracy and low dynamic impedance. The LM385M3X-2.5/NOPB is not intended for continuous operation near its absolute maximum rating.

Can LM385M3X-2.5/NOPB be used in series with other references to generate higher voltages?

No, LM385M3X-2.5/NOPB is a 2-terminal shunt reference and must be connected in parallel with its load-not in series. It regulates voltage across itself by sinking variable current; placing it in series would prevent proper biasing and violate its operational model. To generate higher reference voltages, use a precision op-amp to amplify the LM385M3X-2.5/NOPB output or select a dedicated higher-voltage reference IC. The LM385M3X-2.5/NOPB functions only as a shunt element.

Is LM385M3X-2.5/NOPB RoHS compliant and lead-free?

Yes, LM385M3X-2.5/NOPB is RoHS and Green compliant, with Sn (matte tin) lead finish and no lead content, as confirmed in TI's Package Option Addendum (30-Apr-2024). It meets EU RoHS Directive 2011/65/EU requirements for all 10 restricted substances, including Pb < 0.1% by weight in homogeneous materials. The "NOPB" suffix explicitly denotes lead-free packaging, and the device is qualified for lead-free reflow (Level-1-260C-UNLIM).

What is the thermal resistance (θ_JA) of LM385M3X-2.5/NOPB in its SOT-23 package?

The junction-to-ambient thermal resistance (θ_JA) for LM385M3X-2.5/NOPB in the SOT-23 (DBZ) package is 440°C/W, per TI's thermal characterization data in SNVS743D. This value assumes standard JEDEC test conditions (single-layer board, no copper pour). Actual θ_JA improves significantly with PCB copper area connected to Pin 3 (DAP); adding ≥1 cm² of 2-oz copper under the device can reduce θ_JA to ~120°C/W, critical for maintaining <100°C junction temperature at 20 mA.

Does LM385M3X-2.5/NOPB require an external capacitor for stability?

No, LM385M3X-2.5/NOPB is specifically designed to be stable with up to 10 μF of capacitive loading on its cathode (Pin 2), eliminating the need for external series isolation resistors or stabilization capacitors. This inherent capacitive tolerance simplifies layout and improves reliability in noisy environments. Adding large bulk capacitance (>10 μF) is permissible but offers diminishing returns; the LM385M3X-2.5/NOPB achieves optimal transient response without external compensation.