STMicroelectronics L9953LXP

Overview

L9953LXP from STMicroelectronics is an automotive-grade multifunctional door actuator driver IC integrating five half-bridge outputs and three high-side drivers in a single PowerSSO-36 package. It delivers 0.75A per half-bridge (R_DS(on) = 1600 mΩ), 6A full-bridge capability (R_DS(on) = 150 mΩ), and 6A high-side drive (R_DS(on) = 100 mΩ), with SPI-controlled PWM, open-load/overload diagnostics, and programmable soft-start for inrush current management - deployed in vehicle door lock, mirror fold/defrost, and lighting control subsystems.

For engineers reviewing the L9953LXP datasheet, L9953LXP pinout, L9953LXP application, or L9953LXP equivalent, this device supports microcontroller-driven motor and resistive load control with integrated current monitoring (OUT1/4/5/8), reverse polarity protection via charge pump, and thermal/short-circuit protection across all eight outputs - critical for ASIL-B–aligned body electronics design.

Technical Context

The L9953LXP implements a dual-supply architecture (VS up to 28 V, VCC = 4.5–5.3 V) with independent power domains for analog/digital logic and high-power switching stages. Its SPI interface (24-bit command word, CSN/CLK/DI/DO) enables real-time configuration of output states (forward/reverse/brake/hi-Z), diagnostic readback, and fault flag reporting including overtemperature (T_j ≥ 170 °C shutdown), VS undervoltage (5.7 V turn-on), and open-load detection on all outputs.

Each output features dedicated protection: cross-current prevention (200–400 µs interlock delay), short-circuit robustness, and configurable R_DS(on) modes - e.g., OUT6/OUT7 switch between 500 mΩ (1.5 A sink) and 1800 mΩ (0.35 A sink) based on load requirements. The charge pump (V_CP = VS + 6 to VS + 13 V) drives external N-MOSFETs for reverse-polarity protection, while CM/PWM2 provides bidirectional current sensing or auxiliary PWM input.

Key Specifications

Pinout & Package

Package: PowerSSO-36 - thermally enhanced exposed-pad surface-mount package with 36 leads, optimized for high-current automotive motor drive applications. Requires external connection of all GND, VS, and output pins (e.g., both OUT4 pins must be externally joined) to achieve rated current capability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar door actuator driver applications.

Compared with BD37023FV and VNQ5E050K-E, the L9953LXP uniquely integrates motor + lighting drive, SPI diagnostics, soft-start, and charge pump in one package - reducing system-level component count and enabling ASIL-B–compliant functional safety monitoring without external ICs.

Availability

L9953LXP is available at Aetrix Electronics and suitable for automotive door module assembly, mirror control unit production, and body electronics ECU development requiring stable component supply, long-term lifecycle assurance, and AEC-Q100 Grade 0 qualification.

Supply support for L9953LXP 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 ICs, with over 30 years of automotive qualification expertise and ISO/TS 16949-certified manufacturing.

The L9953LXP belongs to ST's L99 family of automotive smart power drivers, designed specifically for body electronics actuation - emphasizing integration density, diagnostic completeness, and robustness in harsh 12 V/24 V vehicle electrical environments.

FAQ

What is the maximum continuous current rating for OUT4 and OUT5?

OUT4 and OUT5 are rated for ±10.5 A continuous sink/source current at VS = 13.5 V and T_j = 25 °C, with R_DS(on) = 150 mΩ (typ). Derating applies above 25 °C ambient: at T_j = 125 °C, max current drops to ±6 A due to increased on-resistance (200 mΩ typ) and thermal limits. Full rating requires proper PCB copper pour and thermal vias under the PowerSSO-36 exposed pad.

How does the programmable soft-start function operate?

The soft-start is configured via SPI register bits to adjust output slew rate during turn-on, limiting dI/dt for inductive (e.g., motors) and high-inrush resistive (e.g., cold incandescent filaments) loads. It operates independently per output group and prevents bus voltage collapse and electromagnetic interference by controlling gate-drive ramp time - no external components required.

Can the L9953LXP drive a brushed DC motor in both directions without external H-bridge components?

Yes - OUT1, OUT2, and OUT3 are fully integrated half-bridges with complementary high-side and low-side DMOS switches, enabling bidirectional control of brushed DC motors. Each half-bridge supports forward, reverse, brake, and high-impedance states via SPI commands, eliminating need for external discrete H-bridge transistors or gate drivers.

Is the charge pump (CP) pin intended for driving an external MOSFET, and what voltage range does it provide?

Yes - CP is a regulated charge pump output designed to drive the gate of an external N-channel MOSFET used for reverse-polarity protection. It delivers VS + 6 V to VS + 13 V (depending on VS and load), with up to 300 µA output current. This allows use of low-threshold N-MOSFETs instead of less efficient P-MOSFETs or Schottky diodes in the main power path.