STMicroelectronics L9352B-LF

Overview

L9352B-LF from STMicroelectronics is an intelligent quad low-side power switch IC designed for automotive ABS valve control, featuring two 5 A conventional switches (Ch1–Ch2) and two 2.5 A current-regulated outputs (Ch3–Ch4), integrated Z-diode clamping (Ch1–Ch2), free-wheeling diodes (Ch3–Ch4), 0.2 Ω typical R_DS(on), and real-time status monitoring per channel.

For engineers reviewing the L9352B-LF datasheet, L9352B-LF pinout, L9352B-LF application, or L9352B-LF equivalent, this page delivers verified functional context, diagnostic timing behavior, regulator accuracy vs. PWM input ratio, open-load/overtemperature detection thresholds, and PowerSO-36 thermal performance data critical for ABS and brake-by-wire system design.

Technical Context

The L9352B-LF implements four independent low-side output stages: Ch1–Ch2 use DMOS transistors with integrated Zener clamping (V_Z = 45–60 V) for fast inductive energy dissipation in solenoid valves; Ch3–Ch4 employ digital PI regulation (K_P = 0.96, K_I = 0.126) synchronized to a 250 kHz external clock to deliver precise 0–2.25 A output current based on 2 kHz PWM input duty cycle (10–90% range).

Diagnostic architecture includes per-channel push-pull status outputs with inverted logic on fault (e.g., open load, short circuit, recirculation error), dual GND-loss detection (signal-GND and power-GND), selective overtemperature shutdown at T_j = 175–200 °C, and drift detection between regulated channels using synchronized output PWM comparison.

Key Specifications

Pinout & Package

Package: PowerSO-36 with integrated cooling area (ECOPACK®), 175–190 °C max junction temperature during clamping, 2 K/W thermal resistance junction-to-case.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VNQ5E04TR-E and TPS4H160-Q1, the L9352B-LF uniquely integrates both high-current switching (5 A) and precision current regulation (2.25 A) in one PowerSO-36 package with analog-compatible status outputs, making it optimal for automotive safety-critical applications requiring mixed-mode valve control without external sensing or protection components.

Availability

L9352B-LF is available at Aetrix Electronics and suitable for ABS hydraulic control, brake-by-wire actuation, and transmission solenoid management requiring stable component supply across automotive production lifecycles.

Supply support for L9352B-LF 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-grade power ICs, microcontrollers, and sensors, with ISO/TS 16949-certified manufacturing and AEC-Q100 qualified products.

The L9352B-LF belongs to ST's intelligent power switch product line, engineered specifically for ISO 26262-compliant automotive safety systems requiring integrated diagnostics, thermal robustness, and mixed-mode (switch + regulator) load control.

FAQ

What is the maximum allowable supply voltage (V_S) for continuous operation?

The L9352B-LF supports V_S from 4.8 V to 18 V under normal operating conditions. Absolute maximum rating is 40 V, but sustained operation above 18 V risks thermal overstress and violates AEC-Q100 stress limits. The device includes supply loss detection that triggers status inversion below 2 V, ensuring fail-safe response during battery brownout.

How does the current regulator on channels 3 and 4 achieve accuracy without an external sense resistor?

Ch3–Ch4 measure current during the recirculation phase using the voltage drop across the integrated free-wheeling diode path (R_sens = (V_{F_2.25A} – V_{F_250mA})/2 A ≈ 1 Ω). This internal sensing, combined with a digital PI regulator (K_P = 0.96, K_I = 0.126) synchronized to the 250 kHz clock, achieves ±6% accuracy at mid-range currents without external components.

Can the L9352B-LF be used with a 1 MHz clock instead of the specified 250 kHz?

No - the internal regulator and diagnostic filters are designed for 250 kHz clock input. Using 1 MHz violates the f_CLK/f_IN = 125 ratio requirement for current accuracy and causes incorrect timing of t_sf (4–8 µs) and t_lf (16–32 µs) filters, leading to false open-load or short-circuit detections. Clock frequency must remain at 250 kHz ±10%.

What happens during a recirculation error condition on channel 3 or 4?

When D3 or D4 is disconnected or open, the recirculation path fails. The L9352B-LF detects V_rerr ≥ 45 V and immediately shuts down the affected channel's regulator, holding ST3 or ST4 low for the remainder of the input cycle. This prevents uncontrolled current decay and mechanical shock in ABS solenoids, meeting ISO 26262 fault reaction requirements.