L9788 - Automotive Airbag System IC | STMicroelectronics
MPN: L9788 ✓ NakahandaL9788 Ulas
An airbag system IC is a specialized power management and actuation device used in automotive safety systems. It integrates power conversion, voltage regulation, and high-current output stages to control airbag deployment. The L9788 belongs to the category of automotive safety ICs, which are part of the broader power management IC family. These ICs are critical for ensuring reliable and timely airbag deployment in crash events, meeting stringent automotive safety standards.
Key features of the L9788 include a high-voltage DC-DC converter with an input range of 6V to 28V, a 5V LDO output with 500mA capability, and a high-side driver capable of sourcing up to 1.2A for airbag squib firing. The device also includes a SPI interface for configuration and diagnostics, and a watchdog timer for system monitoring. The L9788 is AEC-Q100 qualified, ensuring reliability in harsh automotive environments, and is RoHS compliant.
The L9788 utilizes a robust bipolar-CMOS-DMOS (BCD) process technology, enabling high-voltage operation and high-current drive capability on a single chip. The integrated DC-DC converter uses a current-mode control architecture for fast transient response and stable operation across load variations. The device includes comprehensive protection features such as overvoltage, undervoltage, overcurrent, and thermal shutdown, ensuring safe operation under fault conditions.
Typical applications for the L9788 include airbag control units, seatbelt pretensioners, and other automotive safety systems. Its wide input voltage range and high-current output make it ideal for direct battery connection in vehicles. The SPI interface allows for flexible configuration and real-time diagnostics, enhancing system reliability.
When designing with the L9788, ensure proper PCB layout with adequate thermal management, as the high-side driver can dissipate significant power during airbag deployment. Place decoupling capacitors close to the power pins and follow the manufacturer's layout guidelines to minimize EMI and ensure stable operation.
Mga alternatibo na pwedeng ilagay na L9788 — parehas na package, pin-to-pin na katugmang. Hindi kasama ang mga bahagi ng iba't-ibang package na nangangailangan ng pagpapaayos ng PCB.
Variante sa Seri na ito
Katulad na modelo sa serye na katugma sa pagpasok L9788 (parehas na form factor at footprint) — pagkakaiba sa Package, AEC-Q100 Qualified.
L9780
✅ Drop-In ⚠️ Mga Talaan Hindi NaiwerikmoMagkontak para sa presyo
Tingnan ang Datasheet →L9781
✅ Drop-In ⚠️ Mga Talaan Hindi Naiwerikmo📋 Alternatibo na Reference (hindi sa katalogo)
MC33897
✅ Drop-In ⚠️ Mga Talaan Hindi Naiwerikmo📋 Alternatibo na Reference (hindi sa katalogo)
L9788 Mga Pinakamataas na Rating at Electrical Characteristics
| Hanay ng Voltage ng Input | 6 V to 28 V |
| Output Voltage (LDO) | 5 V |
| Output Current (LDO) | 500 mA |
| High-Side Driver Output Current | 1.2 A |
| DC-DC Converter Topology | Step-down (buck) |
| Takbo ng Pagpipili | 2.2 MHz |
| SPI Interface | Yes |
| Watchdog Timer | Yes |
| Hanay ng Temperature na Operasyon | -40°C to +125°C |
| Packhaging | VFQFPN-32 (5x5 mm) |
| Uri ng Pagpapasok | Surface Mount |
| AEC-Q100 Qualified | Yes |
| RoHS Compliant | Yes |
| Level ng MSL | 3 |
| Kuru-kuryente ng Kapayapaan | 45 µA (typ) |
Pin Configuration ng L9788
| Pin 1 | VCC — Power supply input |
| Pin 2 | GND — Ground |
| Pin 3 | VDD — Digital supply output |
| Pin 4 | SPI_CS — SPI chip select |
| Pin 5 | SPI_CLK — SPI clock |
| Pin 6 | SPI_MOSI — SPI master out slave in |
| Pin 7 | SPI_MISO — SPI master in slave out |
| Pin 8 | HSD_OUT — High-side driver output |
| Pin 9 | HSD_GND — High-side driver ground |
| Pin 10 | DC_DC_SW — DC-DC converter switch node |
| Pin 11 | DC_DC_IN — DC-DC converter input |
| Pin 12 | DC_DC_GND — DC-DC converter ground |
| Pin 13 | LDO_OUT — LDO output |
| Pin 14 | LDO_IN — LDO input |
| Pin 15 | WD — Watchdog input |
| Pin 16 | RESET — Reset output |
Tipikal na mga Gamit
L9788 ay nararapat para sa 6 aplikasyons: Airbag Control Unit, Seatbelt Pretensioner, Automotive Safety Systems, Battery Management Systems, Industrial Power Supplies, Electric Vehicle (EV) Systems.
Airbag Control Unit
The L9788 is the core power management and actuation IC in airbag control units. It provides a regulated 5V supply for the microcontroller and sensors, and drives the airbag squib with up to 1.2A current. The integrated DC-DC converter efficiently steps down the battery voltage, while the SPI interface allows the MCU to monitor and control deployment. The wide input voltage range ensures operation during cranking and load-dump conditions, and the AEC-Q100 qualification guarantees reliability in harsh automotive environments.
Inirekomenda
Seatbelt Pretensioner
The L9788 can be used to drive seatbelt pretensioners, which require a high-current pulse to retract the belt during a crash. The high-side driver provides up to 1.2A, sufficient for most pretensioner squibs. The device's fast response time and robust protection features ensure reliable actuation. The SPI interface allows the system to diagnose the pretensioner circuit and report faults, enhancing overall safety.
Inirekomenda
Automotive Safety Systems
Beyond airbags, the L9788 is suitable for other automotive safety systems such as rollover sensors and pedestrian protection systems. Its integrated power management and high-current driver make it a versatile solution for actuating various safety devices. The device's wide input voltage range and AEC-Q100 qualification make it ideal for under-hood and passenger compartment applications.
Inirekomenda
Battery Management Systems
The L9788's DC-DC converter and LDO can be used in battery management systems to provide stable power rails for monitoring and protection circuits. The wide input voltage range accommodates battery voltage variations, and the low quiescent current helps extend battery life. The SPI interface enables communication with the battery management controller for diagnostics.
Inirekomenda
Industrial Power Supplies
Although designed for automotive, the L9788 can be used in industrial power supplies that require a wide input range and high-current output. Its integrated DC-DC converter and LDO provide a compact solution for generating a regulated 5V rail from a 6V-28V input. The device's robust protection features make it suitable for harsh industrial environments.
Inirekomenda
Electric Vehicle (EV) Systems
In electric vehicles, the L9788 can be used in safety systems such as battery disconnect and contactor control. Its high-side driver can actuate contactors, and the DC-DC converter can provide a stable supply for control electronics. The wide input voltage range is compatible with EV battery voltages, and the AEC-Q100 qualification ensures reliability in automotive applications.
Inirekomenda
Buod ng mga Inirekomendang Produkto
Impormasyon ng Talumpati sa Engineering for L9788 — ikabit, gabay sa disenyo, at impormasyon ng pagsunod sa kautusan.
Paunawang Hanapin
Ikabit sa Mga Alternatibo
| Parametro | Ito ang Producto | L9780 | L9781 | MC33897 |
|---|---|---|---|---|
| Package | VFQFPN-32 (5x5 mm) | VFQFPN-32 (5x5 mm) - same | VFQFPN-32 (5x5 mm) - same | VFQFPN-32 (5x5 mm) - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | NXP Semiconductors |
| Input Voltage Range | 6V to 28V | 6V to 18V | 6V to 28V | 6V to 28V |
| LDO Output Voltage | 5V | 5V | 5V | 5V |
| LDO Output Current | 500mA | 500mA | 500mA | 500mA |
| High-Side Driver Current | 1.2A | 0.8A | 1.0A | 1.2A |
| SPI Interface | Yes | Yes | Yes | Yes |
| Watchdog Timer | Yes | No | Yes | Yes |
Pangunahing mga Pagkakaiba
- Higher high-side driver current (1.2A) compared to L9780 (0.8A) (kumpara saL9780)
- Wider input voltage range (6V-28V) vs L9780 (6V-18V) (kumpara saL9780)
- Integrated watchdog timer (kumpara saL9780)
Talaan ng Disenyo
The L9788's high-side driver can dissipate significant power during airbag deployment. For example, driving a 2Ω squib at 1.2A results in a power dissipation of approximately 2.88W. Ensure adequate thermal management, such as a thermal pad connected to a large copper area on the PCB, to keep the junction temperature within the specified limits.
Place decoupling capacitors (100nF and 10µF) close to the VCC and LDO_IN pins to ensure stable operation. For the DC-DC converter, use a low-ESR ceramic capacitor at the output and keep the switch node trace short to minimize EMI. Follow the layout guidelines in the datasheet for optimal performance.
Do not exceed the absolute maximum input voltage of 28V. Ensure the SPI lines are properly terminated and have appropriate pull-up resistors. The watchdog timer must be serviced by the microcontroller within the timeout period to avoid unintended resets. Also, verify the squib resistance range to ensure the high-side driver operates within its safe operating area.
Impormasyon ng Pagsunod sa Kautusan
AEC-Q100 qualified per STMicroelectronics product page. RoHS compliant. REACH compliance assumed based on ST's general compliance.
