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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Distribution Switches, Load Drivers

STMicroelectronics L9349TR-LF

Name: L9349TR-LF
Brand: STMicroelectronics
SKU: L9349TR-LF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L9349TR-LF

Manufacturer:: STMicroelectronics

Category:: Power Distribution Switches, Load Drivers

Package:: 20-PowerSOIC (0.433", 11.00mm Width)

Datasheet:: L9349TR-LF.pdf

Description:: IC PWR SWITCH N-CHAN 1:1 PWRSO20

Quantity:: RFQ Add To RFQ list

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Inventory:1,033

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Product details

Overview

L9349TR-LF from STMicroelectronics is a quad intelligent low-side power switch IC designed for automotive hydraulic valve control in ABS systems. It integrates four protected output channels: two rated at 5 A / 0.2 Ω (typ.), two at 3 A / 0.3 Ω (typ.), with integrated 50 V Zener clamping, open-load detection in ON/OFF states, and selective overtemperature shutdown.

For engineers reviewing the L9349TR-LF datasheet, L9349TR-LF pinout, L9349TR-LF application, or L9349TR-LF equivalent, this device supports real-time diagnostics including load bypass detection, ground-loss shutdown, slope-controlled switching for EMI reduction, and channel-specific diagnostic outputs-critical for functional safety–oriented automotive power distribution.

Technical Context

The L9349TR-LF implements independent per-channel protection logic with internal current sensing, voltage threshold comparison (VOUV, IOUC), and differential output voltage monitoring (ΔVOUV) to detect open loads and load bypasses. Each channel features dedicated input control (IN1–IN4), enable gating (EN), and diagnostic feedback (D1–D4).

Its thermal management includes selective overtemperature shutdown (180–210 °C trip, 20 °C hysteresis) and overload current limiting (5 A/3 A thresholds) with programmable delay times (tDOL = 6–65 μs). The integrated Zener clamp limits flyback voltage to 50 V during inductive recirculation, while output slope control reduces dV/dt-induced EMI.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Current (Ch1–2)	5 A max (internally limited); supports high-power solenoid valves in ABS actuators
Output Current (Ch3–4)	3 A max (internally limited); suitable for auxiliary or lower-power hydraulic functions
R_DS(on) (Ch1–2)	0.2 Ω typ. @ 25°C; enables low conduction loss and minimal self-heating at full load
R_DS(on) (Ch3–4)	0.3 Ω typ. @ 25°C; balances performance and thermal margin for medium-duty loads
Zener Clamping Voltage	45–60 V; actively clamps inductive kickback to protect MOSFETs and downstream circuitry
Open-Load Detection	Valid in both ON (IOUC = 160–480 mA) and OFF (VOUV = 0.525×VS) states; ensures fail-safe load monitoring
Diagnostic Outputs	D1–D4 provide logic-level fault reporting (short-to-VS, short-to-GND, open load, bypass, GND loss, overtemp)

Pinout & Package

Package: PowerSO-20 (ECOPACK®, lead-free, thermally enhanced with heat sink connected to pins 1, 10, 11, and 20).

Pin/Terminal	Circuit Role	Design Meaning
1, 10, 11, 20 PGND	Power Ground	Low-inductance return path for all four output channels; tied to heatsink for thermal dissipation
2 OUT1	Output 1 (5 A)	High-current low-side switch node for primary ABS valve; supports 50 mJ inductive energy dissipation
3 D1	Diagnostic Output 1	Open-collector status signal indicating fault condition on Channel 1 (e.g., open load, short, overtemp)
4 IN4	Input 4	CMOS-compatible control input for Channel 4; internal pull-down ensures safe-off state if left floating
5 VS	Supply Voltage	Board supply input (4.5–32 V); withstands ISO 7637-2 pulses without functional interruption
6 NC	No Connect	Unbonded pad; must remain unconnected per design
7 IN3	Input 3	CMOS-compatible control input for Channel 3; hysteresis (50–100 mV) rejects noise near logic thresholds
8 D2	Diagnostic Output 2	Open-collector status signal for Channel 2; short-circuit protected up to 16 V
9 OUT2	Output 2 (5 A)	Second high-current output; matched with OUT1 for dual-valve or redundancy configurations
15 GND	Signal Ground	Reference for logic inputs (IN1–IN4, EN); isolated from PGND to avoid noise coupling into control path
16 EN	Common Enable	Global enable/disable for all channels; internal pull-down ensures default-off behavior on power-up or open-wire fault
17 IN1	Input 1	Primary control input for Channel 1; compatible with 5 V microcontroller I/O
18 D4	Diagnostic Output 4	Status reporting for Channel 4; synchronized with diagnostic filter timing (4–24 μs)
19 OUT4	Output 4 (3 A)	Lower-current output optimized for auxiliary loads; shares same protection architecture as other channels

Key Features

Feature	Design Value
Per-channel diagnostic feedback	D1–D4 outputs encode real-time fault type (open load, short, bypass, GND loss, overtemp) without external logic
Integrated active flyback clamping	50 V Zener structure eliminates need for external TVS diodes and reduces PCB area/cost
EMI-reducing output slope control	Programmable dV/dt limits radiated emissions during switching-critical for automotive EMC compliance
Open-load detection in ON and OFF states	Detects disconnected loads regardless of driver state, enabling continuous health monitoring during system idle
Selective thermal shutdown	Shuts down only affected channel(s) above 180–210 °C, preserving functionality of remaining outputs

Applications

ABS Hydraulic Valve Control

Electronic Parking Brake (EPB)

Use Scenario: Driving solenoid-actuated hydraulic valves in anti-lock braking systems to modulate brake pressure per wheel.

IC Role / Device Role / Timing Role: Quad low-side switch providing independent, protected drive for four ABS modulator valves with real-time diagnostics.

Use Value: Enables ISO 26262-compliant functional safety by detecting open circuits, shorts, and thermal faults before brake actuation failure.

Use Scenario: Controlling motorized caliper actuators in electronic parking brake systems requiring fail-safe hold/release sequencing.

IC Role / Device Role / Timing Role: Dual high-current (5 A) channels drive primary brake motors; dual 3 A channels manage auxiliary sensors or latching solenoids.

Use Value: Integrated open-load and bypass detection prevents unintended release due to wiring faults or connector disconnection.

Steering Column Lock (SCL)

Engine Cooling Fan Control

Use Scenario: Engaging/disengaging electromechanical locking mechanisms in steering columns during vehicle start/stop cycles.

IC Role / Device Role / Timing Role: Low-side driver for SCL solenoid with precise current limiting and fast diagnostic response (<65 μs overload detection).

Use Value: Prevents lock malfunction by detecting coil opens, shorts, or overheating before ignition sequence completes.

Use Scenario: Managing multi-speed PWM-controlled cooling fans in engine bays exposed to high ambient temperatures and vibration.

IC Role / Device Role / Timing Role: Robust 3 A/5 A outputs handle fan stall currents; thermal shutdown protects against prolonged overloads.

Use Value: Eliminates need for discrete current-sense amplifiers and external protection ICs-reducing BOM count and layout complexity.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
VNS100N30SH	Single-channel 30 V, 100 mΩ, no integrated diagnostics or multi-channel coordination	Requires four separate ICs + external logic for quad functionality; lacks open-load detection and diagnostic outputs	Only suitable when space, cost, and diagnostic depth are secondary to ultra-low R_DS(on)
TLE7231G	Quad low-side switch with 3.5 A/0.35 Ω (typ.) per channel; no differential load-bypass detection or slope control	Supports basic diagnostics but lacks ΔVOUV-based bypass detection and EMI-optimized slew rate control	Preferred where simpler diagnostics suffice and board-level EMI filtering is already implemented

Compared with VNS100N30SH and TLE7231G, the L9349TR-LF uniquely delivers integrated load-bypass detection, per-channel diagnostic encoding, and output slope control-enabling higher functional safety integrity and reduced system-level EMC design effort in ABS and EPB modules.

Availability

L9349TR-LF is available at Aetrix Electronics and suitable for automotive braking systems, electronic parking brakes, steering column locks, and engine cooling fan control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for L9349TR-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 headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with strong functional safety and AEC-Q100 qualification capabilities.

The L9349TR-LF belongs to ST's intelligent power switch product line, engineered specifically for automotive body and chassis applications demanding high reliability, real-time diagnostics, and robust protection in harsh environments.

FAQ

What is the maximum supply voltage the L9349TR-LF can withstand during transient conditions?

The L9349TR-LF supports up to 45 V supply voltage pulses with duration under 200 ms, complying with ISO 7637-2 pulse 5a requirements for automotive battery line transients. Its absolute maximum DC supply rating is 32 V, and it operates continuously within 4.5–32 V.

How does the L9349TR-LF detect load bypass between channels?

It compares output voltages of paired channels (OUT1 vs. OUT4, OUT2 vs. OUT3) in OFF state using a fixed offset threshold (ΔVOUV = VOC − 1.25 V). If the difference exceeds this value-indicating one load shunted to another-the diagnostic output asserts a specific fault code, suppressing comparison during flyback phases.

Can the L9349TR-LF be used without external flyback diodes?

Yes. Its integrated 50 V Zener clamping structure provides active flyback voltage limitation during inductive turn-off, eliminating the need for external freewheeling diodes in most ABS valve and solenoid applications-reducing component count and board area.

What is the role of the separate signal ground (GND) and power ground (PGND) pins?

GND serves as the reference for logic inputs (IN1–IN4, EN) and diagnostic outputs (D1–D4), isolating sensitive control signals from high-current return paths. PGND pins (1, 10, 11, 20) carry switched load currents and connect directly to the heatsink-minimizing noise coupling and ensuring accurate current sensing and protection triggering.

L9349TR-LF Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: 20-PowerSOIC (0.433", 11.00mm Width)

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Switch Type:: General Purpose

Number of Outputs:: 4

Ratio - Input:Output:: 1:1

Output Configuration:: Low Side

Output Type:: N-Channel

Interface:: On/Off

Voltage - Load:: 4.5V ~ 32V

Voltage - Supply (Vcc/Vdd):: Not Required

Current - Output (Max):: 3A, 5A

Rds On (Typ):: 200mOhm, 300mOhm

Input Type:: Non-Inverting

Features:: Status Flag

Fault Protection:: Open Load Detect, Over Temperature

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PowerSO-20

L9349TR-LF FAQ

1.How can I place an order for L9349TR-LF through Aetrix?

Please submit a Request for Quotation (RFQ) for L9349TR-LF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for L9349TR-LF reliable?

The price and inventory of L9349TR-LF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L9349TR-LF is usually 5 days.

3.What payment methods are accepted for L9349TR-LF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L9349TR-LF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L9349TR-LF?

L9349TR-LF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L9349TR-LF order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for L9349TR-LF?

For technical support, including L9349TR-LF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L9349TR-LF requirements.

6.How does Aetrix verify that L9349TR-LF is sourced from the original manufacturer or authorized distributors?

All L9349TR-LF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that L9349TR-LF meets industry standards.

7.What is the process for return or replacement of L9349TR-LF?

All L9349TR-LF units undergo pre-shipment inspection (PSI). If there is an issue with L9349TR-LF, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The L9349TR-LF part is unused and in its original packaging.

Return procedure for L9349TR-LF:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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