Texas Instruments LM2936MPX-3.3

Overview

LM2936MPX-3.3 from Texas Instruments is a fixed-output 3.3 V ultra-low quiescent current (≤15 μA at 100 μA load) LDO voltage regulator in SOT-223 package, featuring 200 mV typical dropout at 50 mA, ±2% initial output tolerance, and reverse battery protection - designed for automotive and long-life battery-powered systems requiring stable low-power bias.

For engineers reviewing the LM2936MPX-3.3 datasheet, LM2936MPX-3.3 pinout, LM2936MPX-3.3 application, or LM2936MPX-3.3 equivalent, key selection criteria include input voltage range (4.0–40 V), thermal shutdown behavior, ESR-sensitive output capacitor requirements, and compatibility with high-reliability automotive ambient conditions (−40°C to +125°C).

Technical Context

The LM2936MPX-3.3 uses a PNP pass transistor architecture enabling low dropout operation while maintaining ultra-low quiescent current across load and temperature. It integrates reverse battery protection, internal short-circuit current limiting, and thermal shutdown with a typical trip point of 160°C.

Its regulation loop is optimized for stability with low-ESR ceramic or tantalum output capacitors (≥22 µF, ESR ≤8 Ω), and it withstands −50 V reverse transient input for 1 ms - critical for automotive load-dump and cold-crank environments.

Key Specifications

Pinout & Package

SOT-223 package (Package Drawing DCY0004A) with 4 terminals: Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output, Pin 4 = Tab (thermally connected to ground). Exposed tab enhances thermal performance (θJA = 149°C/W, θJC = 36°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS76333QDBVRQ1 and MCP1703T-3302E/MB, the LM2936MPX-3.3 uniquely combines automotive-grade reverse-battery immunity, −50 V transient survival, and ultra-low IQ in a thermally robust SOT-223 package - making it irreplaceable in safety-critical or harsh-environment LDO roles where protection integrity cannot be compromised.

Availability

LM2936MPX-3.3 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, and telematics control units requiring stable component supply with guaranteed long-term availability and RoHS-compliant green packaging.

Supply support for LM2936MPX-3.3 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 delivering analog, embedded processing, and connectivity solutions with deep expertise in power management and automotive electronics.

The LM2936 product line was engineered specifically for automotive and industrial battery-powered systems demanding ultra-low quiescent current, high-voltage resilience, and integrated protection - targeting applications where reliability under electrical stress is non-negotiable.

FAQ

What is the maximum input voltage rating for the LM2936MPX-3.3?

The LM2936MPX-3.3 has a maximum operating input voltage of +40 V and can survive transient inputs up to +60 V and −50 V for 1 ms. Continuous operation above 40 V risks exceeding safe operating area limits and triggering thermal shutdown; therefore, 40 V is the absolute maximum recommended DC input voltage for reliable long-term use of the LM2936MPX-3.3.

Does the LM2936MPX-3.3 include reverse battery protection?

Yes, the LM2936MPX-3.3 includes integrated reverse battery protection and will not conduct or be damaged when subjected to reverse polarity input (e.g., −15 V applied to VIN with GND referenced). This feature eliminates the need for an external series diode in automotive installations where battery terminals may be accidentally reversed during service - a key reliability advantage of the LM2936MPX-3.3.

What output capacitor is required for stable operation of the LM2936MPX-3.3?

The LM2936MPX-3.3 requires a minimum 22 µF output capacitor with effective series resistance (ESR) between 0.3 Ω and 8 Ω for guaranteed stability across temperature and load. Ceramic, tantalum, or polymer capacitors meeting this ESR range are acceptable; aluminum electrolytics are discouraged due to high ESR drift with temperature. The capacitor must be placed as close as possible to the LM2936MPX-3.3 output and ground pins.

Is the LM2936MPX-3.3 pin-compatible with other LM2936 variants?

No - the LM2936MPX-3.3 is in SOT-223 (4-pin) package, while SOIC-8 variants (e.g., LM2936M-3.3) and VSSOP-8 variants (e.g., LM2936MM-3.3) have different pin counts and footprints. There is no pin-to-pin compatibility across these packages. The LM2936MPX-3.3 shares pinout only with other SOT-223 versions like LM2936MP-3.3/NOPB, but not with any SOIC, VSSOP, TO-92, or TO-252 variants of the LM2936 family.

What is the thermal performance of the LM2936MPX-3.3 in its SOT-223 package?

The LM2936MPX-3.3 in SOT-223 has a junction-to-ambient thermal resistance (θJA) of 149°C/W and junction-to-case (θJC) of 36°C/W. With proper PCB layout - including soldering the exposed tab to ≥1 in² of 2 oz. copper - θJA can be reduced significantly. At 50 mA load and 25°C ambient, power dissipation is ~100 mW, resulting in ~15°C junction rise above ambient - well within the −40°C to +125°C operating range of the LM2936MPX-3.3.