STMicroelectronics L9347PD

Overview

L9347PD from STMicroelectronics is an intelligent quad low-side power switch designed for automotive ABS valve control, featuring two 5A conventional switches (Ch1–Ch2) and two 2.5A current-regulated channels (Ch3–Ch4), with integrated Zener clamping (Ch1–Ch2), free-wheeling diodes (Ch3–Ch4), 0.2 Ω/0.35 Ω typical R_DS(on), and real-time status monitoring per channel.

For engineers reviewing the L9347PD datasheet, L9347PD pinout, L9347PD application, or L9347PD equivalent, this device supports precise current regulation (±10% accuracy, 250 mA–2.25 A), open-load detection, selective overtemperature shutdown, recirculation error sensing, and external clock-synchronized PWM control-critical for safety-critical solenoid actuation in braking systems.

Technical Context

The L9347PD implements dual-mode output architecture: Ch1 and Ch2 use DMOS transistors with integrated Zener clamping (V_Z = 45–60 V) for fast inductive energy dissipation in ABS valves; Ch3 and Ch4 employ digital PI regulation (K_P = 0.96, K_I = 0.126) synchronized to a 250 kHz external clock to deliver stable current across 2 kHz input PWM duty cycles (10–90%).

All four channels feature independent push-pull status outputs with inverted logic on fault (e.g., open load, overload, GND loss), while diagnostic filtering uses dual time constants (t_sf = 4–8 μs for short errors; t_lf = 16–32 μs for long errors) and a 10 ms regulation error delay (t_RE) to distinguish transient vs. persistent faults.

Key Specifications

Pinout & Package

Package: PowerSO-36 with integrated cooling area - thermally enhanced exposed die pad for >100 W power dissipation capability in automotive under-hood environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VNS3NV04PTR-E and TPS4H160-Q1, the L9347PD uniquely integrates dual-mode switching (5A + 2.5A regulated), per-channel push-pull status, drift-aware regulation, and ABS-optimized clamping-making it irreplaceable for automotive braking system designs requiring ASIL-B compliance and long-term reliability validation.

Availability

L9347PD is available at Aetrix Electronics and suitable for automotive braking systems, transmission control units, and engine management modules requiring stable component supply, extended temperature operation (−40°C to +150°C), and AEC-Q100 qualification.

Supply support for L9347PD 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 L9347PD belongs to ST's Intelligent Power Switch family, engineered specifically for high-reliability, safety-critical automotive actuators-including ABS, EPB, and transmission solenoids-where integrated diagnostics, thermal robustness, and current regulation are mandatory.

FAQ

What is the maximum continuous current rating for each channel?

Channels 1 and 2 support 5A continuous current with integrated Zener clamping; Channels 3 and 4 support 2.5A regulated current with ±10% accuracy across 250 mA–2.25 A. All channels include short-circuit protection that limits peak current to 7.5A (Ch1–Ch2) or 5A (Ch3–Ch4) before shutdown.

How does the drift detection test mode work?

The drift detection mode (enabled via TEST pin) compares the output PWM duty cycles of Ch3 and Ch4 regulators during identical input conditions. A deviation exceeding ±14.3% triggers a status fault, indicating long-term solenoid resistance shift or aging-critical for detecting ABS valve degradation before failure.

Can the L9347PD operate without an external 250 kHz clock?

No-the 250 kHz external clock is mandatory for Ch3–Ch4 current regulation, clock watchdog operation, and drift detection. If CLK is absent or outside 10–100 kHz range, regulator channels disable and status outputs indicate clock failure; Ch1–Ch2 remain functional as basic switches.

What diagnostic functions are available per channel?

Each channel provides independent open-load detection (V_QU = 0.3–0.36×V_Q), overload detection (I_QO = 5–9A for Ch1–Ch2; 2.5–8A for Ch3–Ch4), GND-loss detection (V_thGND = 0.1–1V), and supply-loss detection (V_Sloss = 2–4.5V), all reported via dedicated push-pull status pins.