Texas Instruments LM2941LDX/NOPB

Overview

LM2941LDX/NOPB from Texas Instruments is a 1-A adjustable low-dropout (LDO) linear voltage regulator in an 8-pin WSON package, delivering output voltages from 5 V to 20 V with typical dropout of 0.5 V at 1 A, quiescent current as low as 30 mA under 5-V input–output differential, and integrated reverse-battery protection - used in automotive body control modules requiring stable 12-V derived rails.

For engineers reviewing the LM2941LDX/NOPB datasheet, LM2941LDX/NOPB pinout, LM2941LDX/NOPB application, or LM2941LDX/NOPB equivalent, key selection criteria include adjustable output range (5–20 V), thermal shutdown and short-circuit protection, ON/OFF logic-level enable control, WSON-8 thermal performance (R_θJA = 40.5°C/W), and reverse-polarity survivability down to −30 V DC.

Technical Context

The LM2941LDX/NOPB implements a PNP-based LDO architecture with trimmed 1.275-V bandgap reference, enabling precise external resistor-set output voltage via ADJ pin. Its quiescent current reduction circuit actively lowers ground current when VIN − VOUT exceeds ~3 V, maintaining 30 mA IQ at 1 A load and 5-V differential.

It integrates overvoltage shutdown (OVSD) triggering at ~30 V, thermal shutdown at ~155°C, and internal short-circuit current limiting (~1.75 A typical). The ON/OFF pin requires TTL/CMOS-compatible active-low logic (≤0.8 V to enable, ≥2 V to disable) with no internal pull-up/down.

Key Specifications

Pinout & Package

LM2941LDX/NOPB uses the WSON-8 (NGN) package: 4.00 mm × 4.00 mm, exposed thermal pad (DAP), leadless surface-mount. Pin 1 is ON/OFF; pins 2 and 7 are GND; pin 3 is IN; pin 5 is OUT; pin 8 is ADJ; pins 4 and 6 are NC (no internal connection - tie to GND or leave floating).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2941T/NOPB, LM2941LDX/NOPB saves board area and improves thermal response via WSON-8 DAP; compared with TPS7A4700RGWR, it trades ultra-low noise for field-programmable output voltage and automotive-grade fault protection.

Availability

LM2941LDX/NOPB is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and telematics gateways requiring stable component supply with extended temperature support and long-lifecycle assurance.

Supply support for LM2941LDX/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, embedded processing, and connectivity technologies, with decades of automotive-qualified product development.

The LM2941 family was designed specifically for harsh-environment vehicular power regulation - emphasizing reverse-battery survival, load-dump immunity, and wide-temperature operation without external protection components.

FAQ

What output voltage range does the LM2941LDX/NOPB support, and how is it set?

The LM2941LDX/NOPB supports an adjustable output voltage range of 5 V to 20 V, set externally using two resistors (R1 and R2) connected to the ADJ pin. The formula is VOUT = 1.275 V × (1 + R2/R1), where R1 is typically 1 kΩ to minimize adjust-pin bias current error. LM2941LDX/NOPB requires no internal trimming - output accuracy depends solely on resistor tolerance and temperature coefficient.

Does the LM2941LDX/NOPB require an output capacitor, and what are its specifications?

Yes, the LM2941LDX/NOPB requires a minimum 22 µF output capacitor with ESR between 100 mΩ and 1 Ω for loop stability. Tantalum capacitors meet this directly; ceramic capacitors require a series resistor (0.1–1 Ω) to emulate ESR. The capacitor must be placed within 1 cm of the OUT and GND pins. LM2941LDX/NOPB becomes unstable without compliant COUT, risking oscillation or poor transient response.

How does the ON/OFF pin function on the LM2941LDX/NOPB, and what logic levels enable it?

The ON/OFF pin on LM2941LDX/NOPB is an active-low enable input with no internal pull-up or pull-down. It enables regulation when pulled ≤0.8 V (typical) and disables output when ≥2 V (typical). To ensure reliable startup, the pin must fall below 0.8 V before VIN reaches regulation threshold. If unused, LM2941LDX/NOPB's ON/OFF pin must be tied directly to GND - floating operation is undefined and may cause erratic behavior.

What thermal design considerations apply to the LM2941LDX/NOPB in its WSON-8 package?

The LM2941LDX/NOPB's WSON-8 package features an exposed thermal pad (DAP) connected to GND (pins 2 and 7). For reliable 1-A operation at 85°C ambient, ≥6 thermal vias must connect the DAP to an internal or bottom-layer ground plane. Without this, R_θJA degrades from 40.5°C/W to >60°C/W, risking thermal shutdown. LM2941LDX/NOPB's thermal performance is highly PCB-layout dependent - AN-1187 (SNOA401) specifies NSMD pad design and via placement.

Is the LM2941LDX/NOPB protected against reverse battery connection, and to what level?

Yes, the LM2941LDX/NOPB includes integrated reverse-battery protection rated for −30 V DC continuous and −75 V transient (≤100 ms). This eliminates the need for an external series diode in automotive applications, preserving efficiency and simplifying bill-of-materials. LM2941LDX/NOPB remains functional after reverse connection and resumes normal operation once polarity is corrected - no latch-up or damage occurs within these limits.