STMicroelectronics L4989MD013TR

Overview

L4989MD013TR from STMicroelectronics is an AEC-Q100-qualified automotive 5 V low-dropout linear voltage regulator with integrated watchdog and reset functions, delivering up to 150 mA output current, 180 mV typical dropout at 150 mA, ±3% output voltage accuracy, and operation across 5.6 V–31 V input range - used to power microcontroller subsystems in engine control units and body electronics.

For engineers reviewing the L4989MD013TR datasheet, L4989MD013TR pinout, L4989MD013TR application, or L4989MD013TR equivalent, this page provides verified technical context, SO-20 package mapping, watchdog timing design values, reset delay programmability, and automotive-grade thermal protection (Tj = −40°C to +150°C) for reliable ECU power management.

Technical Context

The L4989MD013TR implements a p-channel MOSFET pass element enabling stable regulation under input transients up to 40 V, independent of WEn state. Its precision reference is pre-trimmed to achieve ±3% Vo accuracy without external feedback.

Reset supervision operates down to Vo = 1 V with programmable delay (trd = 512 × Tosc, set by external capacitor on Vcr), while the watchdog monitors Wi pulse frequency using a sawtooth oscillator on Vcw - both circuits remain active regardless of WEn logic level.

Key Specifications

Pinout & Package

Package: SO-20 narrow-body surface-mount package (12.6 mm × 7.6 mm × 2.65 mm), ECOPACK®-compliant, with 4 dedicated ground pins (pins 4, 15, 16, and GND pad) for thermal dissipation and noise immunity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive voltage regulator with supervision applications.

Compared with TLFS35584QVVS1, L4989MD013TR offers lower system complexity and cost for basic MCU supervision; versus NCP380LSN33T2G, it delivers full AEC-Q100 compliance, dual supervision, and 5 V precision regulation essential for engine and chassis control.

Availability

L4989MD013TR is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera ECUs, and electric power steering systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for L4989MD013TR 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, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The L4989MD belongs to ST's automotive power management portfolio, engineered specifically for robust, integrated voltage regulation and fault supervision in engine, chassis, and body electronics - prioritizing AEC-Q100 compliance, thermal resilience, and functional safety readiness.

FAQ

What is the maximum input voltage the L4989MD013TR can withstand without damage?

The L4989MD013TR has an absolute maximum DC supply voltage rating of 40 V, verified per Table 3 in DS8714 Rev 3. It safely handles automotive load-dump transients up to this level without external clamping, though continuous operation above 31 V is not specified. The device remains functional across its operating range of 5.6 V–31 V.

How does the reset delay time depend on the external capacitor on the Vcr pin?

Reset delay trd is calculated as trd = 512 × Tosc, where Tosc = [(Vrhth − Vrlth) × Ctr]/Icr + [(Vrhth − Vrlth) × Ctr]/Idr. With Vrhth ≈ 47% Vo, Vrlth ≈ 13% Vo, and Icr/Idr ≈ 8–30 µA, a 1 nF capacitor yields trd = 65–165 ms. This allows precise sequencing of downstream power rails after main supply stabilization.

Can the watchdog function be disabled independently of the voltage regulator?

Yes - asserting WEn (Pin 1) low disables the watchdog circuit while leaving the 5 V regulator and reset supervisor fully operational. Quiescent current drops to 69 µA typ, and Wi input is ignored. This mode is used when MCU self-monitoring suffices and external watchdog overhead is unnecessary.

What thermal performance can be expected with standard PCB layout?

With a 6 cm² copper pour connected to the four GND pins (4, 15, 16) and exposed pad, Rth-jamb is 50°C/W (Table 4). At 150 mA output and 13.5 V input, power dissipation is ~1.3 W, resulting in ΔT ≈ 65°C - keeping Tj within −40°C to +150°C range even at 85°C ambient. No heatsink is required for most automotive applications.