STMicroelectronics L9374TRLF

Overview

L9374TRLF from STMicroelectronics is a SPI-controlled four-channel low-side valve driver IC with integrated freewheeling diodes, designed for automotive solenoid 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 clamping per channel, programmable output timers, and comprehensive diagnostics including open-load, overload, undercurrent, thermal warning/shutdown, and silent valve driver test (SVDT).

For engineers reviewing the L9374TRLF datasheet, L9374TRLF pinout, L9374TRLF application, or L9374TRLF equivalent, this device supports precise timing-critical solenoid actuation in engine management, transmission control, and hydraulic brake systems-where channel-specific duty cycle, current regulation, and real-time fault reporting are essential.

Technical Context

The L9374TRLF implements a dual-mode output architecture: Q1/Q2 operate as high-speed PWM low-side switches with configurable on/off timing, while Q3/Q4 employ closed-loop current control using internal ALU-based error integration and analog measurement blocks (VD, Rs, V_FWD). All four channels share a synchronized 16-bit SPI interface (up to 5 MHz) with parity, command/status buffering, and failure detection logic.

Its diagnostic subsystem monitors 12 distinct fault conditions-including PGND/SGND loss, freewheeling diode loss, CLKIN failure, and current-not-reachable-with configurable filtering times and dedicated status registers. The internal oscillator (±10% tolerance) feeds a clock monitor and synchronization controller enabling precise inter-channel time-shift control (down to 1 µs resolution).

Key Specifications

Pinout & Package

Package: PowerSO-36 (exposed die pad, thermally enhanced SO package with 36 leads).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLE7234SM and VNQ7E100AJTR, the L9374TRLF uniquely combines channel-specific PWM + current regulation, full SPI diagnostics, and SVDT-making it optimal for ASIL-B systems requiring both precision actuation and zero-maintenance validation.

Availability

L9374TRLF is available at Aetrix Electronics and suitable for automotive engine control units, transmission control modules, and electronic brake systems requiring stable component supply, long-term lifecycle support, and AEC-Q100 qualified sourcing.

Supply support for L9374TRLF 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 L9374TRLF belongs to ST's "Automotive Smart Power" product line, engineered specifically for high-reliability solenoid and valve actuation in powertrain and chassis systems-emphasizing functional safety, diagnostic depth, and robustness under harsh automotive environments.

FAQ

What is the maximum continuous output current per channel?

The L9374TRLF supports up to 3.5 A DC per channel (Q1–Q4) under typical thermal conditions (T_A = 85°C, PCB copper area ≥ 200 cm²). Current derating applies above 100°C junction temperature; peak pulsed current reaches 5 A for ≤100 ms with 10% duty cycle. Absolute maximum rating is 6 A, but sustained operation above 3.5 A requires active thermal management.

How does the Silent Valve Driver Test (SVDT) work without actuating the solenoid?

SVDT applies a low-energy, sub-threshold current pulse (<50 mA) through the solenoid coil while monitoring voltage response (V_FD) and sense resistor (R_s) signals. It detects open circuits, shorted turns, and degraded insulation by comparing measured V_FD/R_s ratios against factory-calibrated thresholds-without generating audible noise or mechanical movement, enabling in-vehicle diagnostics during idle.

Can Q1/Q2 and Q3/Q4 be used simultaneously with different control modes?

Yes. All four channels operate concurrently: Q1/Q2 accept 8-bit duty-cycle commands via SPI for standard PWM control, while Q3/Q4 accept 12-bit target current values (0–1000 mA in 1 mA steps) and automatically adjust duty cycle via internal ALU-based current regulation. Timing synchronization between modes is maintained via shared clock and sync-trigger register.

What SPI fault conditions trigger automatic output disable?

Three SPI faults cause immediate channel disable: SPICS timeout (>100 µs inactive), invalid parity on received command, or MISO read-back mismatch after write. Additionally, persistent CLKIN absence (>100 ms) disables all outputs. Fault status is latched in the general status register (address 0, bit 15) and requires explicit clear command before re-enabling.