Texas Instruments LM2937IMPX-2.5

Overview

LM2937IMPX-2.5 from Texas Instruments is a 2.5 V fixed-output, 500-mA low-dropout linear regulator using a PNP pass transistor, featuring 0.5 V typical dropout at full load, ±5% output tolerance over −40°C to 85°C, and integrated reverse-battery, 60-V transient, short-circuit, and thermal overload protection - deployed in automotive body control modules for stable 2.5 V supply to microcontroller I/O or sensor interfaces.

For engineers reviewing the LM2937IMPX-2.5 datasheet, LM2937IMPX-2.5 pinout, LM2937IMPX-2.5 application, or LM2937IMPX-2.5 equivalent, key selection criteria include dropout voltage under 500 mA load, ESR-tolerant stability (up to 3 Ω), quiescent current behavior across input differential, reverse-input protection capability, and thermal performance in SOT-223 packaging for constrained PCB layouts.

Technical Context

The LM2937IMPX-2.5 employs a PNP-based LDO architecture enabling low dropout while maintaining regulation down to 0.5 V (V_IN − V_OUT) at 500 mA. Its internal bandgap reference and error amplifier deliver 2.5 V ±5% accuracy across temperature and load, with dedicated overvoltage shutdown (OVSD) triggering above ~32 V input.

Protection circuitry includes reverse-battery tolerance to −30 V DC and −50 V transients, thermal shutdown at 150°C junction, and foldback current limiting peaking at 1 A. The device operates without enable or UVLO, entering regulation when V_IN ≥ V_OUT + 1 V and achieving optimal dynamic response when V_IN ≥ V_OUT + 2 V.

Key Specifications

Pinout & Package

SOT-223 (DCY) package: 4-pin surface-mount with exposed thermal tab (internally connected to GND), 6.50 mm × 3.5 mm body size, designed for PCB copper plane heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV73325PDBVR and TPS7B6725QPWPRQ1, the LM2937IMPX-2.5 uniquely delivers 500 mA output with 60-V transient and −30-V reverse-battery protection in a cost-optimized SOT-223 package - making it the preferred choice for ruggedized 12 V automotive subsystems where high current and fault resilience are mandatory.

Availability

LM2937IMPX-2.5 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, point-of-load regulation, and legacy system retrofits requiring stable component supply with guaranteed long-term sourcing.

Supply support for LM2937IMPX-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 designing analog ICs, embedded processors, and system-on-chip solutions for industrial, automotive, and personal electronics markets.

The LM2937 product line delivers rugged, feature-rich LDO regulators specifically engineered for harsh-environment automotive and industrial power management - emphasizing fault protection, wide input range, and thermal resilience over basic voltage regulation.

FAQ

What is the maximum input voltage rating for LM2937IMPX-2.5?

The LM2937IMPX-2.5 has an absolute maximum continuous input voltage of 26 V and can withstand transient inputs up to 60 V for ≤100 ms. Operation above 26 V is not recommended, as the overvoltage shutdown (OVSD) circuit disables the output above ~32 V, and prolonged exposure risks reliability degradation. Always maintain VIN ≤26 V for continuous operation.

Does LM2937IMPX-2.5 require an external output capacitor, and what are its specifications?

Yes, the LM2937IMPX-2.5 requires an external output capacitor for stability: minimum 10 µF capacitance with ESR between 10 mΩ and 3 Ω, rated for the full operating temperature range. Ceramic, tantalum, or aluminum electrolytic types are acceptable. The capacitor must be placed as close as possible to the OUTPUT and GND pins to minimize parasitic inductance and ensure loop stability.

What thermal considerations apply to LM2937IMPX-2.5 in SOT-223 packaging?

The LM2937IMPX-2.5 in SOT-223 (DCY) is rated for −40°C to +85°C junction temperature. Its R_θJA is 58.3°C/W with standard PCB layout; thermal performance improves significantly when the exposed TAB (pin 4) is soldered to ≥1 in² of 1-ounce copper. At 500 mA and 3.5 V input, power dissipation is ~0.5 W - requiring adequate copper area to keep junction temperature below 85°C in ambient temperatures up to 70°C.

How does LM2937IMPX-2.5 handle reverse-battery conditions?

The LM2937IMPX-2.5 provides built-in reverse-battery protection, tolerating −30 V DC input with RL = 100 Ω and −50 V transients (tr < 1 ms). This eliminates the need for an external series diode in automotive applications, reducing voltage drop and heat generation. The device remains undamaged and resumes normal operation once polarity is corrected - a key reliability feature for service environments prone to jump-start errors.

Is LM2937IMPX-2.5 pin-compatible with other LM2937 variants?

Yes, all LM2937 variants - including LM2937IMPX-2.5, LM2937IMPX-5.0, and LM2937IMPX-12 - share identical SOT-223 (DCY) pinout (INPUT, GND, OUTPUT, TAB). Output voltage is fixed per variant; no external components are needed for adjustment. This allows board-level substitution across voltage options without layout changes, provided thermal and input voltage constraints are verified for each variant.