L9788 - Automotive Airbag System IC | STMicroelectronics
料号： L9788 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $4.5 | $4.50 |
| 10 | $4.05 | $40.50 |
| 100 | $3.6 | $360.00 |
| 500 | $3.15 | $1,575.00 |
| 1,000 | $2.7 | $2,700.00 |
L9788 概述
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.
直接替换替代料： L9788 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： L9788 （相同外形与封装尺寸） ——差异在于 Package, AEC-Q100 Qualified.
快速对比工具——选择替代料号进行并排对比：
L9780
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$6.8 / 个
查看数据手册 →L9781
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MC33897
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
L9788 最大额定值与电气特性
| 输入电压范围 | 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) |
| 开关频率 | 2.2 MHz |
| SPI Interface | Yes |
| Watchdog Timer | Yes |
| 工作温度范围 | -40°C to +125°C |
| 封装 | VFQFPN-32 (5x5 mm) |
| 安装类型 | Surface Mount |
| AEC-Q100 Qualified | Yes |
| RoHS Compliant | Yes |
| MSL 等级 | 3 |
| 静态电流 | 45 µA (typ) |
L9788 引脚配置
| 引脚 1 | VCC — Power supply input |
| 引脚 2 | GND — Ground |
| 引脚 3 | VDD — Digital supply output |
| 引脚 4 | SPI_CS — SPI chip select |
| 引脚 5 | SPI_CLK — SPI clock |
| 引脚 6 | SPI_MOSI — SPI master out slave in |
| 引脚 7 | SPI_MISO — SPI master in slave out |
| 引脚 8 | HSD_OUT — High-side driver output |
| 引脚 9 | HSD_GND — High-side driver ground |
| 引脚 10 | DC_DC_SW — DC-DC converter switch node |
| 引脚 11 | DC_DC_IN — DC-DC converter input |
| 引脚 12 | DC_DC_GND — DC-DC converter ground |
| 引脚 13 | LDO_OUT — LDO output |
| 引脚 14 | LDO_IN — LDO input |
| 引脚 15 | WD — Watchdog input |
| 引脚 16 | RESET — Reset output |
典型应用
L9788 适用于 6 应用s: 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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
推荐产品汇总
工程参考数据： L9788 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 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 |
关键差异点
- Higher high-side driver current (1.2A) compared to L9780 (0.8A) （对比 L9780)
- Wider input voltage range (6V-28V) vs L9780 (6V-18V) （对比 L9780)
- Integrated watchdog timer （对比 L9780)
设计说明
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.
合规信息
AEC-Q100 qualified per STMicroelectronics product page. RoHS compliant. REACH compliance assumed based on ST's general compliance.
