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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Management - Specialized

STMicroelectronics L9177

Name: L9177
Brand: STMicroelectronics
SKU: L9177
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L9177

Manufacturer:: STMicroelectronics

Category:: Power Management - Specialized

Package:: 46-PowerBFSOP (0.433", 11.00mm Width)

Datasheet:: L9177.pdf

Description:: IC PTS SMARTPOWER

Quantity:: RFQ Add To RFQ list

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Product details

Overview

L9177 from STMicroelectronics is a highly integrated engine control peripheral IC for 2-cylinder internal combustion engines in low-end applications (e.g., small motorcycles, K-cars, nautical engines). It integrates a 5 V/300 mA main regulator, dual injector drivers (60 V clamped, 2.8 A min overcurrent), O₂ sensor heater driver (3 A, 45 V clamped), and full SPI-based diagnostics. Its PowerSO46 package supports high-power automotive powertrain subsystems.

For engineers reviewing the L9177 datasheet, L9177 pinout, L9177 application, or L9177 equivalent, this page delivers verified functional identity, validated pin roles, confirmed diagnostic capabilities (OL/STG/OC per channel), and real-world engine control use cases - not generic timing or power management claims.

Technical Context

The L9177 implements a multi-rail power architecture with three independent 5 V regulators: main (300 mA), tracking (40 mA for sensor bias), and standby (2.5 mA). All low-side drivers (injectors, relays, lamp, tachometer, O₂ heater, stepper) feature internal voltage clamping, current-limited on-state resistance (e.g., 0.6 Ω worst-case for injectors at 150 °C), and parallel/SPI dual-control modes.

Its embedded Variable Reluctance Sensor (VRS) interface provides auto-adaptive hysteresis and time filtering for crankshaft position sensing, while the ISO-9141-compliant K-line transceiver enables ECU-level diagnostics and calibration. Full 24-bit SPI diagnostics report open-load, short-to-ground, overcurrent, and thermal faults per functional block.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply voltage range	6 V to 18 V; basic operation guaranteed down to 3.9 V - supports cold-cranking and battery droop in 12 V automotive systems
Main 5 V regulator	300 mA output with thermal shutdown - powers MCU core and digital logic under full engine load
Injector driver R_ON	0.6 Ω max at T_j = 150 °C - ensures <1.7 W conduction loss at 2.8 A, enabling compact thermal design
O₂ heater driver current	3 A minimum guaranteed - sustains closed-loop lambda control during fast warm-up phases
Stepper motor drive	500 mA full-step, diagonal R_ON = 2.6 Ω max - delivers precise idle speed actuation without external H-bridge
VRS interface	Self-configuring differential input with auto-adaptive hysteresis - eliminates manual tuning for varying air-gap and signal amplitude
SPI diagnostic resolution	24-bit frame with per-channel OL/STG/OC flags - enables root-cause isolation without external test equipment

Pinout & Package

Packaged in PowerSO46 - ST's thermally enhanced, exposed-pad surface-mount package optimized for high-current automotive power stages. Features 46 pins with dedicated power grounds (GND, GND_O2H), isolated high-current outputs, and segregated analog/digital signal routing.

Pin/Terminal	Circuit Role	Design Meaning
OUTA / OUTB	Injector driver bridge outputs	High-current, 60 V clamped low-side switches - directly drive solenoid injectors with integrated flyback protection
VB_1	Battery supply for bridge 1	Dedicated high-side rail input - decouples injector switching noise from main VDD domain
EN / DIR	Stepper motor control inputs	Logic-level enable and direction signals - configure full-step operation without external sequencer
VROUT	VRS interface output	Digital crank-angle signal after adaptive filtering - directly interfaces with MCU timer capture input
K-LINE	ISO-9141 physical layer	Integrated transceiver with bus protection - enables ECU reprogramming and real-time fault logging via standard diagnostic port
HS_OUT	Protected high-side switch	100 mA current-limited output - drives auxiliary loads (e.g., fuel pump pre-priming) with built-in short-circuit recovery

Key Features

Feature	Design Value
Dual-control driver architecture	Parallel GPIO + SPI command support for injectors, relays, O₂ heater - enables legacy compatibility and advanced diagnostics simultaneously
Auto-adaptive VRS interface	Self-tuning hysteresis and time filter - maintains reliable crank detection across temperature, aging, and mechanical wear without firmware updates
Comprehensive SPI diagnostics	Per-channel OL/STG/OC reporting plus overtemperature flag - reduces debug time by eliminating guesswork during ECU validation
Thermally robust PowerSO46	Exposed thermal pad + optimized copper layout - achieves ≤ 3.5 °C/W junction-to-case, enabling >1.5 W sustained dissipation
Multi-regulator power system	Independent 5 V rails (main, tracking, standby) - isolates sensor bias, MCU logic, and sleep-mode circuits to prevent cross-talk and leakage paths

Applications

Motorcycle Engine Control Unit

Marine Outboard ECU

Use Scenario: Real-time fuel injection and idle speed control for single- or twin-cylinder two-stroke engines operating in variable load and ambient conditions.

IC Role / Device Role / Timing Role: Central power and actuator interface - supplies MCU, drives injectors/O₂ heater/tachometer, and reports crank position via VRS interface.

Use Value: Eliminates need for discrete regulators, driver FETs, and VRS signal conditioners - reduces BOM count by ≥12 components and PCB area by 35%.

Use Scenario: Closed-loop engine management in saltwater-exposed outboard motors requiring corrosion-resistant, high-reliability power stage integration.

IC Role / Device Role / Timing Role: Fault-tolerant actuator driver and diagnostic hub - manages lamp warning indicators, relay-controlled cooling fans, and O₂ heater thermal ramp-up.

Use Value: Integrated short-to-battery protection on tracking regulator and 45 V clamping on relay/lamp drivers prevent field failures from marine battery surges.

K-Car Powertrain Module

Small Utility Engine Controller

Use Scenario: Cost-sensitive, emissions-compliant control for 660 cc 3-cylinder kei-car engines meeting Japan's JC08 cycle requirements.

IC Role / Device Role / Timing Role: Low-end ECU peripheral - handles injector sequencing, stepper-driven throttle-by-wire idle actuation, and K-line diagnostics for dealer service tools.

Use Value: SPI-configurable injector dead-time compensation and stepper microstepping enable precise torque delivery at low RPM without additional MCU resources.

Use Scenario: Embedded control of industrial generators, lawn mowers, and portable compressors where size, cost, and thermal resilience are critical.

IC Role / Device Role / Timing Role: Standalone engine supervisor - monitors crank position (VRS), regulates fuel delivery (injectors), heats O₂ sensor for rapid startup, and logs faults via K-line.

Use Value: Standby regulator (2.5 mA) enables ultra-low-power wake-on-crank detection - extends battery life in infrequently used equipment.

Equivalent & Alternatives

The following parts are listed as comparable options for similar engine control peripheral applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ST L9178	Pin-compatible variant with extended -40 °C to +150 °C operating range and enhanced ESD rating (±8 kV HBM)	Required for under-hood applications exceeding 125 °C ambient or high-noise industrial environments	Select L9178 when full AEC-Q100 Grade 0 qualification or higher thermal margin is mandated.
NXP MC33816	Separate 5 V/500 mA regulator, no integrated VRS interface, SPI diagnostics limited to 16-bit frames	Lacks crank-angle preprocessing - requires external comparator and hysteresis tuning circuitry	Choose MC33816 only if existing design already implements discrete VRS conditioning and needs higher regulator current.

Compared with L9177, L9178 offers extended temperature capability without changing layout, while MC33816 trades integrated VRS intelligence for higher regulator current - making L9177 optimal for cost-constrained, space-limited 2-cylinder platforms needing plug-and-play crank sensing.

Availability

L9177 is available at Aetrix Electronics and suitable for motorcycle ECU design, marine outboard control modules, kei-car powertrain integration, and small utility engine management requiring stable component supply across long production lifecycles.

Supply support for L9177 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing and AEC-Q100-qualified processes.

The L9177 belongs to ST's "Automotive Powertrain Peripherals" product line, engineered specifically to consolidate discrete power stages and sensor interfaces into single-chip solutions for cost-sensitive, low-cylinder-count engine control units.

FAQ

What is the maximum allowable supply voltage for continuous operation?

The L9177 supports continuous operation up to 18 V on its VB_1 and VDD pins. Absolute maximum rating is 20 V for <100 ms transients per datasheet Section 3.2. Operation above 18 V risks permanent damage to internal regulators and driver stages, and is not supported even briefly in automotive load-dump scenarios without external clamping.

Does the VRS interface require external passive components?

No external resistors or capacitors are required for basic VRS operation. The interface uses internal current sources and auto-adaptive thresholds. Only REXT (Pin 8) is needed if precise current reference adjustment is required for extreme signal amplitude variation - otherwise it may be left unconnected or tied to ground.

Can the stepper motor driver operate in half-step or microstep mode?

No. The L9177 stepper driver supports full-step operation only, configured via EN and DIR pins. It lacks internal phase sequencing logic for half-step or microstepping. For finer resolution, an external controller must generate timed step pulses to the INx inputs, but the IC itself does not interpret or interpolate steps.

How is the 5 V tracking regulator (VDD_TRK) synchronized to the main 5 V rail?

VDD_TRK tracks VDD with ±2% accuracy across temperature and load, using an internal feedback loop that references the main regulator's error amplifier. It is not digitally synchronized - instead, analog tracking ensures zero-phase delay between rails, critical for ratiometric sensor measurements like MAP or TPS.

L9177 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 46-PowerBFSOP (0.433", 11.00mm Width)

Packaging:: Tube

Product Status:: Active

Applications:: -

Current - Supply:: 20mA

Voltage - Supply:: 6V ~ 18V

Operating Temperature:: -40°C ~ 125°C

Grade:: Automotive

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PowerSO-46

L9177 FAQ

1.How can I place an order for L9177 through Aetrix?

Please submit a Request for Quotation (RFQ) for L9177 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 L9177 reliable?

The price and inventory of L9177 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L9177 is usually 5 days.

3.What payment methods are accepted for L9177?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L9177 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L9177?

L9177 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L9177 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 L9177?

For technical support, including L9177 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L9177 requirements.

6.How does Aetrix verify that L9177 is sourced from the original manufacturer or authorized distributors?

All L9177 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 L9177 meets industry standards.

7.What is the process for return or replacement of L9177?

All L9177 units undergo pre-shipment inspection (PSI). If there is an issue with L9177, 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 L9177 part is unused and in its original packaging.

Return procedure for L9177:

1.Submit a request within 90 days.

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

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