STMicroelectronics L5150CS

Overview

L5150CS from STMicroelectronics is an AEC-Q100 qualified automotive 5 V low-dropout linear voltage regulator with integrated power-on reset, adjustable low-voltage reset, and early warning functions. It delivers 150 mA output current with ±2% output voltage accuracy, 500 mV max dropout at 150 mA, and 55 µA typical quiescent current - designed for engine control units, body electronics, and ADAS domain controllers requiring stable 5 V supply under wide input (5.6–40 V) and temperature (−40 °C to 150 °C) conditions.

For engineers reviewing the L5150CS datasheet, L5150CS pinout, L5150CS application, or L5150CS equivalent, this device is selected for automotive subsystems needing precision 5 V regulation, programmable reset timing via external capacitor, adjustable reset threshold down to 3.5 V, early warning of input voltage sag, and robust thermal/short-circuit protection in SO-8 packaging.

Technical Context

The L5150CS integrates a p-channel MOSFET pass element enabling low dropout (≤500 mV at 150 mA) across its 5.6–40 V input range. Its on-chip trimmed bandgap reference ensures ±2% output voltage accuracy over −40 °C to 150 °C junction temperature, line (VS = 5.6–31 V), and load (0.1–150 mA) variations.

It implements three independent monitoring circuits: a reset block with externally adjustable threshold (via Res_Adj pin and voltage divider) and programmable delay (via Vcr capacitor), an early warning comparator (EWi/EWo) with hysteresis (70 mV), and thermal shutdown activating at 150–190 °C with 10 °C hysteresis - all operating with <1 µA leakage on control pins.

Key Specifications

Pinout & Package

Package: SO-8 (small-outline integrated circuit, 150 mil width, surface-mount). Pin 1 marked by notch or dot; thermal pad not present (unlike PowerSSO-12 variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive LDO with reset and early warning applications.

Compared with TLV70750PDBVR and MAX6467XS29D3+T, the L5150CS uniquely integrates regulation, reset, and early warning in one SO-8 package with AEC-Q100 Grade 0 qualification - reducing board space, component count, and validation effort for automotive power domains.

Availability

L5150CS is available at Aetrix Electronics and suitable for engine control units, body control modules, and ADAS domain controllers requiring stable component supply with automotive-grade reliability, long-term lifecycle support, and traceable sourcing.

Supply support for L5150CS 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 microcontrollers, power management ICs, sensors, and automotive-grade analog devices.

The L5150CS belongs to ST's automotive power management portfolio, engineered specifically for 12 V/24 V vehicle electrical systems needing high-accuracy, low-quiescent-current regulation with built-in functional safety features like reset and early warning.

FAQ

What is the minimum input voltage required for regulation at full 150 mA load?

The L5150CS maintains regulation down to VS = Vo + Vdp = 5.0 V + 0.5 V = 5.5 V at 150 mA, per datasheet Table 5 (Vdp max = 500 mV). At lighter loads, dropout decreases - e.g., <100 mV at 10 mA - enabling operation during deep cold-crank events where battery voltage sags to 3.5 V, provided output current is reduced accordingly.

Can the reset threshold be set below 3.5 V?

No. The Res_Adj pin's internal reference and comparator architecture limit the adjustable reset threshold to a minimum of 3.5 V, as specified in the "Description" section and confirmed by Res_Adj voltage range (0.4–1.3 V low, 2.35–2.65 V typical) in Table 6. Attempting lower thresholds via external divider violates absolute maximum ratings and invalidates AEC-Q100 compliance.

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

Yes - the Vcr pin requires an external capacitor to ground to generate the reset delay. Without it, reset assertion occurs immediately upon output undervoltage (no delay). Datasheet Figure 24 shows the timing diagram, and Table 6 specifies Trd = 4 ms typical with 1000 pF. Omitting the capacitor disables programmable delay, reverting to instantaneous reset.

How does the early warning feature interact with the reset function?

Early warning (EWi/EWo) and reset (Res) operate independently: EWi monitors VS directly via external divider and asserts EWo when input sags below ~2.5 V; Res monitors Vo and asserts when output drops below the Res_Adj-set threshold (e.g., 4.5 V). This allows staged response - EWo triggers firmware save or state backup ~100 ms before Res asserts full system reset, enabling graceful shutdown.