Texas Instruments LM2941T/LB04

Overview

LM2941T/LB04 from Texas Instruments is a 1-A adjustable low-dropout (LDO) linear voltage regulator with 5 V to 20 V output range, 0.5 V typical dropout at 1 A, −40°C to +125°C operating temperature, and integrated reverse-battery protection. It serves as the primary post-regulation stage in automotive power supplies where input rails vary from 6 V to 26 V.

For engineers reviewing the LM2941T/LB04 datasheet, LM2941T/LB04 pinout, LM2941T/LB04 application, or LM2941T/LB04 equivalent, key selection criteria include dropout performance under 1 A load, ON/OFF control compatibility with TTL/CMOS logic, quiescent current reduction above 3 V VIN–VOUT differential, thermal shutdown behavior at 155°C, and WSON-8 package thermal vias implementation for industrial ambient conditions.

Technical Context

The LM2941T/LB04 uses a PNP pass transistor architecture enabling 1 A continuous output with dropout as low as 0.5 V at 25°C and ≤1 V across full temperature range. Its internal bandgap reference (1.275 V typical) sets output via external R1/R2 divider, supporting precise 5–20 V adjustment without trimming.

It integrates three protection modes: overvoltage shutdown (OVSD) triggers at ~30 V input, thermal shutdown activates at ~155°C junction temperature, and short-circuit current limiting holds peak output at 1.6–1.9 A. The ON/OFF pin operates with TTL/CMOS-compatible thresholds (ON ≤0.8 V, OFF ≥2 V) and draws ≤100 μA.

Key Specifications

Pinout & Package

LM2941T/LB04 is packaged in an 8-lead WSON (NGN) surface-mount package measuring 4.00 mm × 4.00 mm with exposed thermal pad (DAP) connected to pins 2 and 7 (GND). The DAP must be soldered to PCB ground plane using ≥6 thermal vias for thermal compliance per AN-1187.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2941CT, LM2941T/LB04 offers extended temperature range and automotive qualification; compared with TPS7A4700RGWR, it provides integrated reverse-battery and overvoltage protection but higher output noise - making LM2941T/LB04 optimal for cost-constrained, protection-critical automotive LDO roles.

Availability

LM2941T/LB04 is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power rails, and telematics GPS receivers requiring stable component supply with long lifecycle assurance and AEC-Q100 compliance.

Supply support for LM2941T/LB04 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, embedded processing, and power management ICs, with decades of automotive-grade product development and manufacturing expertise.

The LM2941x family was designed specifically for vehicular power regulation - integrating reverse-battery protection, load-dump resilience, and wide-temperature operation to replace discrete protection solutions in ECUs and body control modules.

FAQ

What is the maximum input voltage the LM2941T/LB04 can withstand without damage?

The LM2941T/LB04 has an absolute maximum input survival voltage of 60 V for ≤100 ms, per its datasheet. However, its recommended maximum operational input voltage is 26 V DC. Exceeding 26 V continuously risks triggering overvoltage shutdown (~30 V threshold) and degrading long-term reliability. For sustained operation, keep VIN ≤26 V; transient spikes up to 60 V are survivable if duration is strictly limited.

How do I set the output voltage of the LM2941T/LB04 to 12 V?

To set LM2941T/LB04 output to 12 V, use the formula VOUT = VREF × ((R1 + R2)/R1), where VREF = 1.275 V typical. With R1 = 1 kΩ (recommended to minimize bias error), solve for R2: R2 = 1 kΩ × (12 V / 1.275 V − 1) ≈ 8.4 kΩ. Use a standard 8.45 kΩ, 1% metal-film resistor. Place R1 between ADJ and GND, R2 between OUT and ADJ, and ensure both resistors have matched tempcos.

Does the LM2941T/LB04 require an output capacitor, and what type is recommended?

Yes, LM2941T/LB04 requires a minimum 22 µF output capacitor with ESR between 100 mΩ and 1 Ω for loop stability. A tantalum capacitor meeting these specs is preferred. Alternatively, a 22 µF X5R/X7R ceramic capacitor may be used only if a 0.1–1 Ω series resistor is added to emulate required ESR. The capacitor must be placed within 1 cm of the OUT and GND pins.

Can the LM2941T/LB04 be used in a reverse-voltage protection circuit without external components?

Yes, LM2941T/LB04 includes integrated reverse-battery protection and can withstand −30 V DC and −55 V transient reverse input without external diodes. This eliminates the 0.3–0.7 V forward drop and heat dissipation of traditional series Schottky diodes, improving efficiency in always-on automotive modules like alarm controllers or telematics units.

What thermal design practices are required for the LM2941T/LB04 in WSON-8 package?

For LM2941T/LB04 in WSON-8 (NGN) package, the exposed DAP (pins 2 & 7) must be soldered to a dedicated PCB ground plane with ≥6 thermal vias (0.3 mm diameter) connecting to inner ground layers. Per AN-1187, use NSMD copper pads and avoid solder mask over the DAP area. This achieves RθJA ≈ 40.5°C/W - essential to maintain TJ ≤125°C at 1 A load in 85°C ambient.