STMicroelectronics L4949EDTRWTR

Overview

L4949EDTRWTR from STMicroelectronics is a monolithic 5 V low-dropout linear voltage regulator with integrated power-on reset, input voltage sense comparator, and preregulator functions-designed for microcomputer-controlled automotive systems. It operates from 5 V to 28 V DC supply, delivers up to 100 mA output current, maintains ±1% output accuracy at 5 V, and achieves dropout voltage under 0.5 V at 100 mA load.

For engineers reviewing the L4949EDTRWTR datasheet, L4949EDTRWTR pinout, L4949EDTRWTR application, or L4949EDTRWTR equivalent, key selection criteria include its 40 V transient tolerance, programmable reset delay via external capacitor, 1.23 V internal sense reference, and SO-8 TP package compatibility with automotive-grade thermal and ESD requirements.

Technical Context

The device integrates three functional blocks: a PNP-based LDO regulator with foldback current limiting, a voltage-sense comparator referenced to 1.23 V (±100 mV hysteresis), and a reset circuit triggered when VOUT falls below 4.5 V with user-adjustable delay (55–180 ms via CT pin capacitor). All blocks share a common SO-8 TP substrate with GND-connected thermal pad.

Its preregulator output (VZ) stabilizes internal bias at ~5 V and supports noise reduction when decoupled with ≤1 µF capacitor-enabling stable operation during sub-8 V transients. Thermal shutdown activates at 165 °C, and absolute maximum ratings include 40 V transient supply (≤1 s) and 200 °C/W junction-to-ambient thermal resistance in SO-8.

Key Specifications

Pinout & Package

Package: SO-8 TP (ECOPACK® compliant, 1.27 mm pitch, 5.0 × 6.2 mm body, exposed thermal pad).

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP1117ST50T3G and TLV70733PDQNR, L4949EDTRWTR uniquely combines 5 V regulation, 40 V transient tolerance, integrated reset with programmable delay, and dual-rail supervision in a single SO-8 package-reducing design complexity and validation effort for automotive microcontroller power domains.

Availability

L4949EDTRWTR is available at Aetrix Electronics and suitable for body control modules, engine control units, infotainment systems, and ADAS sensor hubs requiring stable component supply across automotive production lifecycles.

Supply support for L4949EDTRWTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with broad AEC-Q100 qualification coverage.

L4949EDTRWTR belongs to ST's automotive voltage regulator product line, engineered specifically for microcontroller power domains in harsh-temperature, high-transient environments-emphasizing functional safety, long-term supply stability, and integrated supervision.

FAQ

What is the maximum allowable input voltage for continuous operation?

The L4949EDTRWTR supports continuous DC input from 5 V to 28 V. Its absolute maximum rating permits 40 V for transients lasting ≤1 second, such as ISO 7637-2 Pulse 5a. Operation above 28 V beyond this limit risks permanent damage due to exceeding junction temperature or internal breakdown limits.

Can the VZ pin be used as a secondary output supply?

No-VZ is an internally generated bias rail (~5 V) with ≤10 µA output capability. ST explicitly states it must not be loaded as a functional output. Connecting loads >10 µA causes regulation loss and may destabilize internal circuitry. Use only for optional noise filtering via capacitor to GND.

How does the sense comparator function in a typical automotive application?

The SI pin monitors input voltage via an external resistor divider. When SI drops below 1.16 V, the open-collector SO pin pulls low, signaling microcontroller firmware of impending undervoltage. This enables predictive shutdown or safe state entry before VOUT collapses-critical for preserving EEPROM writes or CAN bus arbitration integrity.

Is the L4949EDTRWTR qualified to AEC-Q100 standards?

While the datasheet confirms automotive-grade design, thermal specs (−40 °C to +150 °C T_J), and ISO 7637-2 compliance, ST does not list explicit AEC-Q100 certification for L4949E in Doc ID 4275 Rev 6. Customers requiring formal qualification should consult ST's latest automotive product roadmap or request PPAP documentation directly from ST.