STMicroelectronics L4988DTR

Overview

L4988DTR from STMicroelectronics is an AEC-Q100 qualified automotive 5V low-dropout voltage regulator with integrated reset and watchdog functions, delivering 200mA output current, 500mV max dropout at 200mA, ±2% output voltage tolerance, and operation across 5.6V–31V input range - used to power microprocessor subsystems in engine control units and body electronics.

For engineers reviewing the L4988DTR datasheet, L4988DTR pinout, L4988DTR application, or L4988DTR equivalent, key selection considerations include its programmable reset delay (via external capacitor on Vcr), adjustable watchdog timeout (via Vcw), thermal shutdown at 150°C, enable-controlled watchdog activation, and SO-8 package suitability for space-constrained automotive PCB layouts.

Technical Context

The L4988DTR implements a p-channel MOSFET pass element enabling regulation down to 500mV dropout at full 200mA load while maintaining stability under 40V transient surges. Its internal pre-trimmed reference ensures ±2% output accuracy over −40°C to +150°C junction temperature.

Reset and watchdog circuits operate independently: reset triggers when Vo falls below 6–10% of nominal (adjustable via external resistor divider), with reaction time as fast as 2µs below 4V; watchdog monitors Wi input frequency and asserts Res low if pulses stall beyond Twop (25–90ms, set by Ctw on Vcw), configurable only when WEn is high.

Key Specifications

Pinout & Package

Supplied in SO-8 package (8-pin small outline, 1.27 mm pitch, exposed pad for thermal dissipation). Pin mapping validated per STMicroelectronics DS5334 Rev 8, Figure 2 and Table 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP380LSN33T2G and TLV70733PDQNR, the L4988DTR uniquely integrates AEC-Q100-compliant 5V regulation, programmable reset, and configurable watchdog in one SO-8 device - eliminating external components and enabling single-chip MCU power supervision in harsh environments.

Availability

L4988DTR is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera systems, and electric power steering sensor interfaces requiring stable component supply across automotive production lifecycles.

Supply support for L4988DTR 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 specializing in automotive, industrial, and power management solutions, with broad portfolio of AEC-Q100-qualified analog and power ICs.

The L4988 belongs to ST's automotive voltage regulator family designed specifically for robust, integrated power-supply supervision in engine, chassis, and safety-critical electronic control units.

FAQ

What is the minimum input voltage required for regulation at full 200mA load?

The L4988DTR maintains regulation down to 5.6V input across its full operating temperature range. At 200mA load and 25°C, the dropout is typically 270mV, meaning Vo remains stable as long as Vs ≥ 5.27V - but the absolute minimum specified for guaranteed function is 5.6V per datasheet Section 2.3.

How does the reset output behave when the output voltage drops below 1V?

When Vo falls below 1V, the Res pin remains low but loses guaranteed timing behavior; however, the datasheet specifies that reset reaction time improves dramatically to 2µs in this condition, ensuring fastest possible fault signaling for critical brown-out recovery sequences.

Can the watchdog and reset functions operate independently?

Yes - reset monitors Vo continuously regardless of WEn state, while watchdog functionality is fully enabled only when WEn is high. With WEn low, the watchdog circuit is disabled, reducing quiescent current and preventing unintended Res assertion due to Wi signal loss.

Is an external capacitor required on the Vcr pin for basic reset operation?

No - the reset circuit functions without external capacitor on Vcr, asserting Res immediately upon Vo falling below Vo_th. The Vcr capacitor adds programmable delay (trd) to the release edge only; omission results in immediate high-to-low transition on Vo recovery.