L9780-TR - Automotive Airbag System IC | STMicroelectronics
MPN: L9780-TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $10 | $1,000.00 |
| 500 | $9 | $4,500.00 |
| 1,000 | $8.1 | $8,100.00 |
L9780-TR Overview
An airbag system IC is a specialized power management and actuation device that controls the deployment of airbags in a vehicle. It typically includes squib drivers that provide the precise current pulse needed to ignite the airbag inflator, a boost converter to generate the high voltage required for deployment, and diagnostic circuitry to ensure system readiness. The L9780-TR sits within the broader hierarchy of automotive safety electronics, which includes sensors, the ACU, and the airbag modules themselves. As a critical safety component, it must comply with stringent automotive standards such as AEC-Q100 and ISO 26262.
Key features of the L9780-TR include multiple squib driver channels, each capable of delivering a controlled deployment current, and an integrated DC-DC boost converter that generates the high voltage (typically 20-35V) needed for squib firing. The device also includes comprehensive diagnostic functions, such as open-load and short-to-battery detection, which are essential for ensuring system integrity. The SPI interface allows the microcontroller to configure the device and read status registers, enabling real-time monitoring and fault management.
From a technical perspective, the L9780-TR leverages STMicroelectronics' advanced BCD (Bipolar-CMOS-DMOS) process technology, which combines high-voltage capability with low-power digital logic. This architecture enables efficient power conversion and precise current control while maintaining low quiescent current for battery-powered automotive applications. The device is designed to operate over a wide input voltage range, typically from 6V to 18V, accommodating both 12V and 24V vehicle electrical systems. Its thermal management is optimized for the high peak currents during deployment, with a package designed to dissipate heat effectively.
Typical applications for the L9780-TR include driver and passenger airbag systems, side airbags, curtain airbags, and seatbelt pretensioners. In these systems, the L9780-TR ensures reliable and timely deployment, which is critical for occupant safety. The device is also used in advanced driver assistance systems (ADAS) that require pyrotechnic actuators for pedestrian protection or battery disconnect.
When designing with the L9780-TR, engineers must pay careful attention to the layout of the high-voltage boost converter and the squib driver outputs. Proper grounding and decoupling are essential to minimize noise and ensure stable operation. Additionally, the SPI interface must be configured correctly to enable diagnostic features and avoid unintended deployments. The device's safety features, such as over-temperature and over-current protection, should be considered in the system design to enhance overall reliability.
Drop-in alternatives for L9780-TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with L9780-TR (same form factor and footprint) — differing in Function.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
L9780
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.8 / Unit
View Datasheet →L9781
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
L9782
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
L9780-TR Specifications
| Function | Airbag system IC |
| Input Voltage Range | 6 V to 18 V |
| Boost Converter Output Voltage | 20 V to 35 V |
| Interface | SPI |
| Operating Temperature Range | -40C to +125C |
| Mounting Type | Surface Mount |
| Qualification | AEC-Q100 |
| RoHS Status | Compliant |
| Diagnostic Features | Open-load, short-to-battery detection |
| Protection Features | Over-temperature, over-current |
| Process Technology | BCD |
L9780-TR Pin Configuration
| Pin 1 | VCC — Power supply input |
| Pin 2 | GND — Ground |
| Pin 3 | SPI_CS — SPI chip select |
| Pin 4 | SPI_CLK — SPI clock |
| Pin 5 | SPI_MOSI — SPI master out slave in |
| Pin 6 | SPI_MISO — SPI master in slave out |
| Pin 7 | SQUIB1 — Squib driver output 1 |
| Pin 8 | SQUIB2 — Squib driver output 2 |
| Pin 9 | BOOST_OUT — Boost converter output |
| Pin 10 | BOOST_IN — Boost converter input |
Typical Applications
L9780-TR is suitable for 6 applications: Driver Airbag System, Passenger Airbag System, Side Airbag System, Curtain Airbag System, Seatbelt Pretensioner, Pedestrian Protection System.
Driver Airbag System
The L9780-TR is used in driver airbag systems to control the deployment of the driver's airbag. It provides the necessary squib driver channels and high-voltage boost converter to ensure reliable and timely inflation. The device's diagnostic features monitor the squib circuit for faults, ensuring the system is ready for deployment. Its wide input voltage range and AEC-Q100 qualification make it suitable for the harsh automotive environment. The SPI interface allows the ACU to configure and monitor the device, enabling precise control over the deployment process. The L9780-TR's integrated protection features, such as over-temperature and over-current protection, enhance system reliability and safety.
Recommended
Passenger Airbag System
In passenger airbag systems, the L9780-TR manages the deployment of the passenger airbag, which typically requires a larger inflator and higher deployment energy. The device's boost converter generates the high voltage needed for squib firing, while its multiple squib driver channels can support dual-stage inflators. The diagnostic features ensure that any fault in the squib circuit is detected and reported to the ACU, preventing unintended deployment. The L9780-TR's robust design and AEC-Q100 qualification make it a reliable choice for this safety-critical application. The SPI interface enables seamless integration with the ACU, allowing for real-time monitoring and control.
Recommended
Side Airbag System
The L9780-TR is also used in side airbag systems, which protect occupants during side-impact collisions. These systems often require faster deployment times and may use multiple squibs. The L9780-TR's high-voltage boost converter and multiple driver channels enable rapid and reliable deployment. The device's diagnostic capabilities are crucial for detecting faults in the squib circuits, which could compromise safety. Its compact package and surface-mount design allow for integration into space-constrained side airbag modules. The L9780-TR's wide operating temperature range ensures performance in extreme conditions, making it suitable for automotive applications.
Recommended
Curtain Airbag System
Curtain airbag systems, which deploy from the roof to protect occupants' heads, require precise and reliable deployment. The L9780-TR provides the necessary squib drivers and boost converter to ensure the airbag inflates correctly. The device's diagnostic features monitor the squib circuits, ensuring they are ready for deployment. Its SPI interface allows the ACU to configure the device and read status, enabling advanced safety functions. The L9780-TR's robust design and AEC-Q100 qualification make it ideal for this critical safety application. The device's thermal management is optimized for the high peak currents during deployment, ensuring reliable operation.
Recommended
Seatbelt Pretensioner
The L9780-TR is used in seatbelt pretensioner systems, which tighten the seatbelt during a collision to reduce occupant movement. These systems require a single squib driver and a high-voltage pulse to ignite the pretensioner. The L9780-TR's boost converter generates the required voltage, while its squib driver delivers the precise current. The device's diagnostic features ensure the pretensioner circuit is functional, enhancing safety. Its compact size and surface-mount package allow for integration into the seatbelt mechanism. The L9780-TR's wide input voltage range and AEC-Q100 qualification make it suitable for automotive use.
Recommended
Pedestrian Protection System
In pedestrian protection systems, the L9780-TR is used to deploy pyrotechnic actuators that lift the hood to reduce injury to pedestrians. This application requires a reliable and fast deployment mechanism. The L9780-TR's squib drivers and boost converter provide the necessary energy for actuation. The device's diagnostic features monitor the actuator circuits, ensuring they are ready for deployment. Its SPI interface allows the ACU to control the system and receive status updates. The L9780-TR's robust design and AEC-Q100 qualification make it suitable for this safety-critical application, which is becoming increasingly common in modern vehicles.
Recommended
Recommended Products Summary
Engineering reference data for L9780-TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9780 | L9781 | L9782 |
|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
Key Differentiators
- Integrated boost converter and squib drivers in a single IC (vs Discrete solutions)
- AEC-Q100 qualification (vs Non-automotive grade ICs)
- Comprehensive diagnostic features (vs Simpler squib drivers)
Design Notes
For the L9780-TR, ensure proper grounding and decoupling of the power supply pins. Use a low-ESR ceramic capacitor (e.g., 100nF) close to the VCC pin and a larger bulk capacitor (e.g., 10uF) for the boost converter input. The high-voltage boost output should have a dedicated ground return to minimize noise.
The L9780-TR can dissipate significant power during squib firing. Ensure adequate thermal relief on the PCB, such as a copper pour under the device and thermal vias to the ground plane. The operating temperature range is -40C to +125C, so thermal management is essential for reliable operation.
Avoid exceeding the absolute maximum ratings for the boost converter output voltage. Ensure the SPI interface is properly configured to prevent unintended deployment. Always implement a hardware interlock or safety mechanism to avoid accidental squib firing during testing or maintenance.
Compliance Information
RoHS compliant per STMicroelectronics. AEC-Q100 qualified for automotive applications.
