STMicroelectronics L9348

Overview

L9348 from STMicroelectronics is a monolithic quad low-side driver in Multipower-BCD technology, designed to switch inductive loads such as automotive relays and solenoid valves. It integrates two 5A and two 3A DMOS power switches with on-resistances of 0.2 Ω (Q1/Q2) and 0.35 Ω (Q3/Q4), output voltage clamping up to 40 V, and real-time diagnostics including overload, overtemperature, and ground-loss detection.

For engineers reviewing the L9348 datasheet, L9348 pinout, L9348 application, or L9348 equivalent, this device supports high-reliability automotive and industrial control systems requiring independent channel monitoring, integrated recirculation diodes for 3A channels, and CMOS-compatible 3.3 V inputs with status feedback per channel.

Technical Context

The L9348 implements four independent low-side switching stages using DMOS transistors, each with dedicated diagnostic feedback via open-drain status outputs (ST1–ST4). Its protection architecture includes current-sense-based overload detection (5–9 A for Q1/Q2; 3–8 A for Q3/Q4), thermal shutdown at 175–210 °C, and dual ground-loss sensing (signal-GND loss threshold: 150–510 mV; power-GND loss: 1.5–3.5 V).

Each channel features digitally filtered error detection with configurable reset timing: latch-type faults (overload, overtemperature, GND loss) require manual reset via ENA/IN deassertion ≥1.5 ms, while transient faults (open load, active clamp) auto-reset after the same delay. The 3A channels (Q3/Q4) integrate freewheeling diodes rated for 3 A peak reverse current and 0.5–1.75 V forward drop.

Key Specifications

Pinout & Package

Package: PowerSO-36 (exposed die pad, 15.8–16.0 mm × 13.9–14.5 mm, 1.1 mm height), thermally optimized for high-power dissipation in automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad low-side driver applications.

Compared with VNQ7E120AJ and TLE7234SE, the L9348 offers unique integration of freewheeling diodes on its 3A channels, eliminating external components for solenoid loads, while maintaining pin-compatible diagnostics and simpler 3.3 V CMOS interfacing without SPI overhead.

Availability

L9348 is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC output stages, heavy-duty relay replacement boards, and engine management auxiliary load control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for L9348 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 manufacturing and qualification capabilities.

The L9348 belongs to ST's Automotive Power Switch family, engineered specifically for robust, diagnostics-rich control of inductive loads in harsh environments where reliability, thermal resilience, and functional safety readiness are essential.

FAQ

What is the maximum continuous output current per channel?

The L9348 supports 5 A continuous current on channels Q1 and Q2, and 3 A on Q3 and Q4, verified under Tj ≤150 °C and VS ≥9.5 V. Derating applies above 125 °C junction temperature, where RDSON rises to 0.5 Ω (Q1/Q2) and 0.75 Ω (Q3/Q4), limiting practical current to ~3.5 A and ~2.3 A respectively at 150 °C.

How does the integrated freewheeling diode function on Q3/Q4?

The integrated diodes D3 and D4 provide a recirculation path for inductive energy during Q3/Q4 turn-off, rated for 3 A peak reverse current and 0.5–1.75 V forward voltage at −1.5 A. They eliminate external diode requirements for solenoid and valve loads, but are absent on Q1/Q2-those channels rely on internal voltage clamping or external diodes.

Can the L9348 be used with 5 V logic inputs?

Yes-the IN1–IN4 and ENA inputs accept 2–6 V high-level signals and tolerate −1.5 V to 6 V, making them compatible with both 3.3 V and 5 V CMOS logic. Input hysteresis (50–100 mV) ensures noise immunity, and pull-down current (8–40 μA at VIN = 5 V) guarantees defined LOW state for unconnected inputs.

What happens during signal-ground loss detection?

Signal-ground loss triggers immediate driver shutdown and status inversion when voltage between GND and PGND drops below 150–510 mV. The fault is latched until ENA or the corresponding INx is held LOW for ≥1.5 ms, ensuring system-level recovery only after root-cause correction-not just transient noise.