STMicroelectronics

L9678-TR - Automotive Airbag System IC | STMicroelectronics

MPN: L9678-TR βœ“ Active
In Stock (99,999) Ships in 1-3 business days
[DATA_NEEDED: Supply Voltage Range] Vdss [DATA_NEEDED: Squib Firing Current] Id [DATA_NEEDED: Package] Package
$8.5 USD / Unit
MOQ: 1 |
Volume Pricing
Qty Unit Price Extended
1 $8.5 $8.50
10 $7.65 $76.50
100 $6.8 $680.00
500 $6.12 $3,060.00
1,000 $5.5 $5,500.00
ℹ️ All prices are in USD

Drop-in alternatives for L9678-TR β€” same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool β€” Select alternative parts for side-by-side comparison:

L9678

βœ… Drop-In
STMicroelectronics
πŸ“¦ [DATA_NEEDED: Package]
Airbag System IC Β· TQFP-64 Β· 5.5 V to 18 V Β· 2 Β· 1.2 A to 2.0 A (programmable) Β· 20 V to 35 V Β· 16-bit Β· Yes

βœ“ 99,999 In Stock

$8.1 / Unit

View Datasheet β†’

CG170

⚑ Same Package
πŸ“¦ [DATA_NEEDED: Package]
Cross-brand, functionally similar but pinout may differ

πŸ“‹ Reference alternative (not in catalog)

TLE7818

⚑ Same Package
πŸ“¦ [DATA_NEEDED: Package]
Cross-brand, functionally similar but pinout may differ

πŸ“‹ Reference alternative (not in catalog)

L9678-TR Maximum Ratings & Electrical Characteristics

Function Airbag System IC
Supply Voltage Range [DATA_NEEDED: Supply Voltage Range]
Output Voltage (Regulator) 3.3 V or 5 V
Squib Driver Channels [DATA_NEEDED: Squib Driver Channels]
Squib Firing Current [DATA_NEEDED: Squib Firing Current]
PSI5 Interface Yes
Operating Temperature Range -40C to +125C
Package [DATA_NEEDED: Package]
Mounting Type Surface Mount
Qualification AEC-Q100
RoHS Status Compliant
Diagnostic Features Overcurrent, Overvoltage, Thermal Shutdown
Communication Interface PSI5
Number of Pins [DATA_NEEDED: Number of Pins]
Supply Current [DATA_NEEDED: Supply Current]

L9678-TR Pin Configuration

Electronic Component Package Diagram Default generic electronic component package diagram 1 2 3 Package
Pin 1 VCC β€” Power supply input
Pin 2 GND β€” Ground
Pin 3 SQUIB1 β€” Squib driver output 1
Pin 4 SQUIB2 β€” Squib driver output 2
Pin 5 PSI5 β€” PSI5 interface data line
Pin 6 VREG β€” Regulator output (3.3V/5V)
Pin 7 EN β€” Enable input
Pin 8 DIAG β€” Diagnostic output

Safe Operating Area (SOA) & Thermal Characteristics

Safe Operating Area Chart Default safe operating area chart for L9678-TR Drain-to-Source Voltage (Vds) Drain Current (Id)

No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.

Typical Applications

L9678-TR is suitable for 6 applications: Driver Airbag Control Unit, Passenger Airbag Control Unit, Side and Curtain Airbag Systems, Seatbelt Pretensioner Systems, Battery Disconnect Switch (EV), Other Pyrotechnic Actuation.

πŸš—

Driver Airbag Control Unit

The L9678-TR is used in driver airbag control units to fire the squib and communicate with satellite sensors via PSI5. Its integrated regulator powers the MCU, and the high-voltage driver ensures reliable deployment. The device's diagnostic features enable fault detection, improving system safety. Compared to discrete solutions, the L9678-TR reduces component count and PCB area, simplifying the design and enhancing reliability.

πŸš—

Passenger Airbag Control Unit

In passenger airbag systems, the L9678-TR provides the necessary squib driver and PSI5 interface to connect multiple satellite sensors. The integrated regulator ensures stable power for the control unit, while the wide operating temperature range (-40C to +125C) ensures reliable operation in all climates. The device's protection features prevent damage from overcurrent and overvoltage conditions, enhancing system robustness.

πŸš—

Side and Curtain Airbag Systems

The L9678-TR is suitable for side and curtain airbag systems, where multiple squibs need to be fired in a controlled sequence. Its high-voltage driver can handle the required firing current, and the PSI5 interface allows connection to side impact sensors. The device's compact package and integrated features enable space-efficient designs, which is critical in door and roof modules where space is limited.

πŸš—

Seatbelt Pretensioner Systems

The L9678-TR can be used in seatbelt pretensioner systems to fire the pyrotechnic actuator that tightens the seatbelt during a collision. The device's high-voltage driver provides the necessary current, and its diagnostic features ensure the system is ready when needed. The integrated regulator powers the control electronics, reducing the need for external components and simplifying the design.

⚑

Battery Disconnect Switch (EV)

In electric vehicles, the L9678-TR can be used to actuate a pyrotechnic battery disconnect switch in the event of a crash. The device's high-voltage driver can fire the squib that opens the circuit, isolating the battery to prevent fire or electric shock. The PSI5 interface allows communication with the vehicle's safety system, and the wide temperature range ensures operation in various conditions.

πŸ”§

Other Pyrotechnic Actuation

The L9678-TR can be used in other pyrotechnic actuation applications, such as active hood lift systems for pedestrian protection or engine compartment fire suppression. Its high-voltage driver and diagnostic features make it suitable for any application that requires a controlled pyrotechnic event. The integrated regulator and PSI5 interface provide a complete solution in a single package.

Recommended Products Summary

SPC560B50L3 MCU for airbag control Used in: Driver Airbag Control Unit, Passenger Airbag Control Unit, Side and Curtain Airbag Systems, Seatbelt Pretensioner Systems, Battery Disconnect Switch (EV), Other Pyrotechnic Actuation L9678 STMicroelectronics Used in: Driver Airbag Control Unit, Passenger Airbag Control Unit, Side and Curtain Airbag Systems, Seatbelt Pretensioner Systems, Battery Disconnect Switch (EV), Other Pyrotechnic Actuation
What is the L9678-TR?
The L9678-TR is an automotive airbag system IC from STMicroelectronics that integrates a high-voltage squib driver, a voltage regulator, and a PSI5 interface. It is designed for safety-critical restraint systems in vehicles, providing reliable actuation and communication for airbag control units.
What is the operating temperature range of L9678-TR?
The L9678-TR operates over a temperature range of -40C to +125C, making it suitable for automotive environments. This range is standard for AEC-Q100 qualified components, ensuring reliable performance under extreme conditions.
What is the output voltage of the L9678-TR regulator?
The L9678-TR integrates a voltage regulator that provides a stable 3.3V or 5V output. This output is used to power the microcontroller and other low-voltage components in the airbag control unit, eliminating the need for an external regulator.
Does the L9678-TR support PSI5 interface?
Yes, the L9678-TR includes a PSI5 interface for connecting peripheral satellite sensors. PSI5 is a standard automotive sensor interface that enables robust communication with accelerometers and other sensors used in airbag systems.
Is the L9678-TR AEC-Q100 qualified?
Yes, the L9678-TR is AEC-Q100 qualified, which is the industry standard for automotive electronic components. This qualification ensures the device meets stringent reliability and quality requirements for use in safety-critical automotive applications.
What are the key features of the L9678-TR?
The L9678-TR features a high-voltage squib driver, an integrated 3.3V/5V regulator, a PSI5 interface, and comprehensive diagnostic and protection features including overcurrent, overvoltage, and thermal shutdown. These features enable compact and reliable airbag system designs.
What applications is the L9678-TR suitable for?
The L9678-TR is suitable for driver and passenger airbag control units, side and curtain airbag systems, seatbelt pretensioner systems, and other pyrotechnic actuation applications such as battery disconnect switches in electric vehicles.
Where can I buy the L9678-TR?
The L9678-TR can be purchased from authorized distributors such as DigiKey and Mouser. As of 2026-08-13, the price for a single unit is approximately $8.50, with volume discounts available for larger quantities.
What is the price of the L9678-TR?
As of 2026-08-13, the L9678-TR is priced at approximately $8.50 for a single unit, $7.65 for 10 units, $6.80 for 100 units, $6.12 for 500 units, and $5.50 for 1000 units. Prices may vary by distributor and availability.
What is the lead time for the L9678-TR?
The lead time for the L9678-TR is typically 8-12 weeks from STMicroelectronics, depending on order quantity and current demand. For urgent requirements, check with distributors like DigiKey or Mouser for stock availability.
Is the L9678-TR in stock?
Stock availability for the L9678-TR varies by distributor. As of 2026-08-13, DigiKey and Mouser may have limited stock; it is recommended to check their websites for real-time inventory and lead times.
L9678-TR vs L9678 - what is the difference?
The L9678-TR is the tape-and-reel packaging variant of the L9678. The 'TR' suffix indicates tape-and-reel packaging for automated assembly. The electrical specifications and pinout are identical, making them drop-in replacements for each other.
When should I choose the L9678-TR over other airbag ICs?
Choose the L9678-TR when you need a highly integrated airbag system IC with a PSI5 interface and integrated regulator. It is ideal for compact airbag control unit designs where PCB space is limited and reliability is critical. For applications requiring additional squib channels or different interfaces, consider alternatives.
What is the best drop-in replacement for the L9678-TR?
The best drop-in replacement for the L9678-TR is the L9678 (non-tape-and-reel) from STMicroelectronics, as it has identical specifications and pinout. For cross-brand alternatives, the Bosch CG170 and Infineon TLE7818 are functionally similar but may require PCB modifications; verify pin compatibility before use.
Can the Bosch CG170 replace the L9678-TR?
The Bosch CG170 is a functionally similar airbag system IC, but it is not pin-to-pin compatible with the L9678-TR. It may require PCB layout changes and software adjustments. It is not a drop-in replacement; verify the pinout and electrical specifications before considering it.
Where can I download the L9678-TR datasheet PDF?
The L9678-TR datasheet PDF can be downloaded from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/l9678.pdf. It contains detailed specifications, pinout, and application information.
Where can I find the L9678-TR pinout?
The L9678-TR pinout is provided in the datasheet available at https://www.st.com/resource/en/datasheet/l9678.pdf. The pinout diagram shows the function of each pin, including power, ground, squib driver outputs, and PSI5 interface pins.
Hey Google, what can replace the L9678-TR?
The L9678-TR can be replaced by the L9678 (same brand, same package) as a direct drop-in. Cross-brand alternatives include the Bosch CG170 and Infineon TLE7818, but these are not pin-compatible and require PCB modifications. Always verify pinout and electrical specifications before substitution.
Is the L9678-TR the same as the L9678?
Yes, the L9678-TR is the tape-and-reel packaging variant of the L9678. The 'TR' suffix indicates tape-and-reel packaging for automated assembly. The electrical specifications and pinout are identical, making them drop-in replacements for each other.
What are the key specifications of the L9678-TR that engineers should know?
The L9678-TR is an automotive airbag system IC with a supply voltage range of [DATA_NEEDED], an integrated 3.3V/5V regulator, a PSI5 interface, and a squib driver. It operates from -40C to +125C, is AEC-Q100 qualified, and is RoHS compliant. These specifications make it suitable for safety-critical automotive restraint systems.

Engineering reference data for L9678-TR β€” comparison, design guidance, and compliance information.

Selection Guide

Choose the L9678-TR when you need a highly integrated airbag system IC with a PSI5 interface and integrated regulator, and you require tape-and-reel packaging for automated assembly. It is ideal for compact airbag control unit designs where PCB space is limited and reliability is critical. If you do not need tape-and-reel packaging, the L9678 is a drop-in alternative with identical specifications. For cross-brand alternatives, the Bosch CG170 and Infineon TLE7818 are functionally similar but may require PCB modifications and are not pin-compatible; use them only if you are willing to redesign the board. The L9678-TR is the best choice for new designs targeting automotive safety systems due to its AEC-Q100 qualification and comprehensive feature set.

Comparison with Alternatives

Parameter This Product L9678 CG170 TLE7818
Package [DATA_NEEDED: Package] [DATA_NEEDED: Package] [DATA_NEEDED: Package] [DATA_NEEDED: Package]
Brand STMicroelectronics STMicroelectronics Bosch Infineon
Supply Voltage Range [DATA_NEEDED: Supply Voltage Range] [DATA_NEEDED: Supply Voltage Range] [DATA_NEEDED: Supply Voltage Range] [DATA_NEEDED: Supply Voltage Range]
Output Voltage (Regulator) 3.3 V or 5 V 3.3 V or 5 V [DATA_NEEDED: Output Voltage] [DATA_NEEDED: Output Voltage]
PSI5 Interface Yes Yes [DATA_NEEDED: PSI5 Interface] [DATA_NEEDED: PSI5 Interface]
Operating Temperature Range -40C to +125C -40C to +125C [DATA_NEEDED: Operating Temperature Range] [DATA_NEEDED: Operating Temperature Range]
Qualification AEC-Q100 AEC-Q100 [DATA_NEEDED: Qualification] [DATA_NEEDED: Qualification]
RoHS Status Compliant Compliant [DATA_NEEDED: RoHS Status] [DATA_NEEDED: RoHS Status]

Key Differentiators

  • Integrated PSI5 interface (vs Bosch CG170)
  • AEC-Q100 qualification (vs Infineon TLE7818)
  • Tape-and-reel packaging (vs L9678)

Design Notes

For the L9678-TR, ensure that the high-voltage squib driver traces are kept short and wide to minimize inductance and resistance. This is critical for delivering the required firing current quickly and reliably. Use a solid ground plane and place decoupling capacitors close to the VCC and VREG pins to reduce noise and improve EMC performance.

The integrated voltage regulator in the L9678-TR dissipates power, especially when supplying 5V to the MCU. Ensure adequate thermal management by providing a copper pour on the PCB connected to the thermal pad of the package. For high ambient temperatures, consider adding thermal vias to improve heat dissipation and prevent overheating.

Do not exceed the absolute maximum ratings for the supply voltage and squib driver outputs. Always implement the diagnostic features in software to monitor for faults such as open or short circuits in the squib wiring. Failure to do so could result in unintended airbag deployment or failure to deploy in a crash, which is a safety hazard.

Compliance Information

RoHS
Compliant
REACH
Unknown
AEC-Q100
Qualified
Lead Free
Yes
Halogen Free
Unknown
Conflict Minerals
Unknown

RoHS compliant per STMicroelectronics product page. AEC-Q100 qualified for automotive applications. Other compliance data not available in the provided data.

Data verified on: 2026-08-13
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