STMicroelectronics L9374LF

Overview

L9374LF from STMicroelectronics is a SPI-controlled four-channel protected low-side valve driver IC with integrated freewheeling diodes, designed for automotive solenoid and injector control. It features two 140 mΩ PWM-controlled outputs (Q1/Q2) and two 250 mΩ current-regulated outputs (Q3/Q4) with ±6% accuracy, 35 V Zener clamp protection, programmable output timers, and comprehensive diagnostics including open-load, overload, undercurrent, thermal warning/shutdown, and silent valve test capability.

For engineers reviewing the L9374LF datasheet, L9374LF pinout, L9374LF application, or L9374LF equivalent, this device is selected for precision current-controlled fuel injector actuation, high-reliability solenoid sequencing in engine management systems, and diagnostic-critical valve control where load monitoring and fault isolation are mandatory.

Technical Context

The L9374LF implements a dual-mode output architecture: Q1 and Q2 operate as PWM-controlled low-side switches with 140 mΩ R_DS(on), while Q3 and Q4 use closed-loop current regulation with 250 mΩ power stages and ±6% setpoint accuracy. All channels integrate recirculation diodes and 35 V Zener clamping for inductive load protection.

Its 16-bit SPI interface (up to 5 MHz) supports full-duplex diagnosis reporting, register-based configuration of duty cycle, current target, duration timing, and synchronization parameters. Internal clock monitoring, ALU-based BIST, and Silent Valve Driver Test (SVDT) enable functional safety compliance in ASIL-B–capable systems.

Key Specifications

Pinout & Package

Package: PowerSO-36 - thermally enhanced exposed-pad SO package with 36 leads, optimized for high-power dissipation in automotive under-hood environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPIC2101-Q1 and VNQ7E100AJTR, the L9374LF uniquely delivers per-channel current regulation, silent valve testing, and full SPI-configurable timing-making it the only option for ASIL-B–compliant GDI and transmission control where diagnostic completeness and precision actuation are mandatory.

Availability

L9374LF is available at Aetrix Electronics and suitable for automotive engine control units, transmission control modules, and exhaust aftertreatment systems requiring stable component supply, long-term lifecycle support, and AEC-Q100 qualified performance.

Supply support for L9374LF 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 AEC-Q100 qualification coverage.

The L9374LF belongs to ST's SPC5 automotive power driver family, engineered specifically for high-diagnostic-integrity valve and solenoid control in engine management and transmission systems where functional safety and field reliability are paramount.

FAQ

What is the maximum continuous output current per channel for the L9374LF?

The L9374LF does not specify a single "maximum continuous current" rating due to thermal dependency on PCB layout and ambient conditions. Per datasheet Table 7, the absolute maximum pulsed current is 4.5 A (t_p ≤ 100 µs), while continuous DC current is limited by junction temperature: at T_A = 85°C with typical PCB copper area, Q1/Q2 sustain ~2.2 A and Q3/Q4 ~1.8 A before thermal shutdown activates at 150°C.

Does the L9374LF support daisy-chained SPI communication?

Yes - the L9374LF supports daisy-chained SPI via its SPICS, MOSI, MISO, and SPICLK pins. Multiple devices can share one SPI bus using individual chip select lines or cascaded MISO/MOSI routing. The datasheet confirms compatibility with standard SPI mode 0 (CPOL=0, CPHA=0) and specifies setup/hold times for reliable multi-device timing at up to 5 MHz.

How does the Silent Valve Driver Test (SVDT) function without actuating the load?

SVDT applies a brief, sub-threshold current pulse (<10 mA) through the output stage while measuring voltage drop across the load. If the load is open, the measured V_D exceeds threshold; if intact, the voltage remains within expected range. This occurs during standby with Qx fully off, producing no audible click or mechanical movement - confirmed in Section 4.8.13 and Table 39 of the datasheet.

Can Q1–Q4 be driven independently, or must they be synchronized?

All four channels can be driven fully independently: each has dedicated duration registers (addresses 4–5), duty cycle registers (6–9), and current target registers (10–13). Synchronization is optional and configurable via Sync + Sync-trigger register (address 0); unsynchronized operation allows staggered actuation for noise reduction or thermal load spreading, as detailed in Section 4.3.2.