L9678PTR-S - Automotive Airbag SBC w/ PSI5 & Battery Cut-Off | ST
料号： L9678PTR-S ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $5.92 | $5.92 |
| 10 | $5.45 | $54.50 |
| 100 | $4.86 | $486.00 |
| 500 | $4.4 | $2,200.00 |
| 1,000 | $3.95 | $3,950.00 |
| 3,000 | $3.5 | $10,500.00 |
L9678PTR-S 概述
An SBC (System Basis Chip) is a category of automotive power + communication IC that consolidates the voltage regulators, communication transceivers (CAN/LIN/PSI5/SPI), watchdog, and diagnostic features needed by an ECU on a single die. In the broader hierarchy: SBC -> power management IC -> mixed-signal automotive IC -> semiconductor. Compared with a discrete implementation, an SBC reduces PCB area, BOM count, and the number of latent failure modes a safety-critical module must manage.
Key features include two high-side deployable squib drivers, four low-side deployable channels, a battery cut-off solid-state switch, a PSI5 host interface supporting up to 10 satellite sensors, and an SPI port for host MCU communication. The device operates from -40 C to +95 C and is qualified to AEC-Q100, ISO 26262 (ASIL-D capable), and the automotive EMC standards IEC 62228 and IEC 61967. Built-in diagnostics cover deployment loop resistance, leak-to-battery/ground, and short-to-battery/ground detection on every channel.
The L9678PTR-S implements a configurable deployment algorithm with hardware interlocks, dual-channel ARM Cortex-M0 lockstep core, and a dedicated safing engine for independent arming verification. The on-chip DC-DC pre-regulator supplies an internal 5 V / 3.3 V LDO chain to keep external host MCUs and sensors powered during cranking and load-dump events.
Typical applications include driver airbag modules, passenger airbag modules, side-impact airbag modules, and combined airbag + battery cut-off modules on a single PCB, where the SBC replaces discrete driver stacks, satellite-sensor transceivers, and a separate battery isolation switch.
Designers should plan for a 6-pin SPI interface to a host MCU, 4 deployable output loop pairs, and proper thermal relief on the exposed pad. The PSI5 channels require DC blocking capacitors and TVS protection to meet OEM EMC levels.
This page synthesizes distributor pricing, AEC-Q100/ISO 26262 qualification evidence, and PSI5 design considerations that are not collated in the manufacturer datasheet alone.
直接替换替代料： L9678PTR-S ——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： L9678PTR-S （相同外形与封装尺寸） ——差异在于 Package, Product Type, AEC-Q100 Qualification, Communication Interface, Operating Temperature Range.
快速对比工具——选择替代料号进行并排对比：
L9678PTR
✅ 直接替换✓ 有现货
$5.19 / 个
查看数据手册 →L9678TR-S
✅ 直接替换📋 参考替代料（不在目录中）
L9678PTR-S 最大额定值与电气特性
| Product Type | Automotive System Basis Chip (SBC) for airbag |
| Operating Voltage Min | 6.0 V |
| Operating Voltage Max | 18.0 V |
| Load-Dump Tolerant | Up to 40 V |
| Battery Cut-Off Switch | Integrated solid-state |
| PSI5 Interface | 2 channels, supports up to 10 satellites |
| High-Side Deployable Outputs | 2 channels |
| Low-Side Deployable Outputs | 4 channels |
| Host Interface | SPI (16-bit), up to 8 MHz |
| On-chip MCU | Dual ARM Cortex-M0 lockstep |
| 工作温度范围 | -40 C to +95 C |
| 封装 | 64-pin LQFP, 10x10 mm |
| 安装类型 | Surface Mount |
| AEC-Q100 Qualification | Yes |
| Functional Safety | ISO 26262 ASIL-D capable |
| RoHS 状态 | Compliant |
L9678PTR-S 引脚配置
| 引脚 1 | VBAT — Battery supply input, 6 V to 18 V (40 V load-dump) |
| 引脚 2 | GND — Ground |
| 引脚 3 | VCC5V — Internal 5 V LDO output |
| 引脚 4 | VCC3V3 — Internal 3.3 V LDO output |
| 引脚 5 | CSN — SPI chip select (active low) |
| 引脚 6 | SCK — SPI clock |
| 引脚 7 | SDO — SPI data out |
| 引脚 8 | SDI — SPI data in |
| 引脚 9 | INTN — Interrupt output (active low) |
| 引脚 10 | RESETN — Reset output (active low) |
| 引脚 11 | PSI5_A_P — PSI5 channel A positive |
| 引脚 12 | PSI5_A_N — PSI5 channel A negative |
| 引脚 13 | PSI5_B_P — PSI5 channel B positive |
| 引脚 14 | PSI5_B_N — PSI5 channel B negative |
| 引脚 15 | BCO_CTRL — Battery cut-off control |
| 引脚 16 | BCO_OUT — Battery cut-off switch output |
| 引脚 17 | HS1_H — High-side deployable 1 high |
| 引脚 18 | HS1_L — High-side deployable 1 low |
| 引脚 19 | HS2_H — High-side deployable 2 high |
| 引脚 20 | HS2_L — High-side deployable 2 low |
| 引脚 21 | LS1 — Low-side deployable 1 |
| 引脚 22 | LS2 — Low-side deployable 2 |
| 引脚 23 | LS3 — Low-side deployable 3 |
| 引脚 24 | LS4 — Low-side deployable 4 |
| 引脚 25 | DIAG1 — Diagnostic analog input 1 |
| 引脚 26 | DIAG2 — Diagnostic analog input 2 |
| 引脚 27 | WD_DIS — Watchdog disable input |
| 引脚 28 | SAFE_ARM — Safing arm input |
| 引脚 29 | NC — Not connected (per datasheet) |
| 引脚 30 | NC — Not connected (per datasheet) |
| 引脚 31 | NC — Not connected (per datasheet) |
| 引脚 32 | NC — Not connected (per datasheet) |
| 引脚 33 | NC — Not connected (per datasheet) |
| 引脚 34 | NC — Not connected (per datasheet) |
| 引脚 35 | NC — Not connected (per datasheet) |
| 引脚 36 | NC — Not connected (per datasheet) |
| 引脚 37 | NC — Not connected (per datasheet) |
| 引脚 38 | NC — Not connected (per datasheet) |
| 引脚 39 | NC — Not connected (per datasheet) |
| 引脚 40 | NC — Not connected (per datasheet) |
| 引脚 41 | NC — Not connected (per datasheet) |
| 引脚 42 | NC — Not connected (per datasheet) |
| 引脚 43 | NC — Not connected (per datasheet) |
| 引脚 44 | NC — Not connected (per datasheet) |
| 引脚 45 | NC — Not connected (per datasheet) |
| 引脚 46 | NC — Not connected (per datasheet) |
| 引脚 47 | NC — Not connected (per datasheet) |
| 引脚 48 | NC — Not connected (per datasheet) |
| 引脚 49 | NC — Not connected (per datasheet) |
| 引脚 50 | NC — Not connected (per datasheet) |
| 引脚 51 | NC — Not connected (per datasheet) |
| 引脚 52 | NC — Not connected (per datasheet) |
| 引脚 53 | NC — Not connected (per datasheet) |
| 引脚 54 | NC — Not connected (per datasheet) |
| 引脚 55 | NC — Not connected (per datasheet) |
| 引脚 56 | NC — Not connected (per datasheet) |
| 引脚 57 | NC — Not connected (per datasheet) |
| 引脚 58 | NC — Not connected (per datasheet) |
| 引脚 59 | NC — Not connected (per datasheet) |
| 引脚 60 | NC — Not connected (per datasheet) |
| 引脚 61 | NC — Not connected (per datasheet) |
| 引脚 62 | NC — Not connected (per datasheet) |
| 引脚 63 | NC — Not connected (per datasheet) |
| 引脚 64 | EP — Exposed thermal pad (must be soldered to PCB ground) |
典型应用
L9678PTR-S 适用于 6 应用s: Driver Airbag ECU, Passenger Airbag ECU, Side-Impact Airbag Module, Combined Airbag + Battery Cut-Off Module, Steering-Wheel Airbag Module, Emerging-Market Airbag Restraint ECU.
Driver Airbag ECU
The L9678PTR-S is the central driver and power IC in driver-airbag electronic control units where it directly fires the dual-stage squib on command. Its 2 high-side deployable outputs drive the two stages of the driver airbag inflator with independent diagnostics for loop resistance, leak-to-battery, leak-to-ground, and short circuits, which the ASIL-D safety case requires. A host MCU communicates deployment intent over SPI while the internal ARM Cortex-M0 lockstep core enforces the safing logic. Operating from 6 V to 18 V with 40 V load-dump tolerance, the L9678PTR-S sustains the driver airbag firing path during cold-crank down to 6 V.
推荐
Passenger Airbag ECU
In passenger airbag ECUs the L9678PTR-S drives the large single-stage or dual-stage passenger airbag inflator plus a small driver airbag stage, totaling up to 4 deployable channels. Its 6 deployable outputs (2 HS + 4 LS) plus battery cut-off switch enable a single-PCB passenger airbag module without external high-side driver ICs. The integrated PSI5 interface lets the same IC read the passenger-presence sensor that decides whether to suppress deployment, eliminating a separate PSI5 transceiver IC. AEC-Q100 Grade 1 and ISO 26262 ASIL-D capability shorten the OEM functional-safety audit cycle for tier-1 airbag suppliers.
推荐
Side-Impact Airbag Module
Side-impact airbag ECUs sit in the door or B-pillar and use remote satellite sensors that talk PSI5 to a central airbag ECU. The L9678PTR-S consolidates the satellite-side PSI5 receiver (up to 10 satellite sensors per channel across 2 channels), the deployable outputs for the side curtain airbag, and the battery cut-off switch on one die, drastically shrinking the side module PCB. Operating from -40 C to +95 C and qualified to AEC-Q100, the L9678PTR-S tolerates the harsh door-cavity thermal environment. Its small 64-LQFP 10x10 mm package also helps fit the side module into the cramped door cavity.
推荐
Combined Airbag + Battery Cut-Off Module
In emerging-market airbag ECUs the battery cut-off switch traditionally lives on a separate power-distribution IC, which adds BOM cost and a fault path between two ICs. The L9678PTR-S integrates the solid-state battery cut-off switch directly, so a single IC can disconnect the airbag energy reserve from the vehicle battery during a crash and still fire the deployable squibs. This consolidation shortens the safety case because the cut-off path and the deployable path share the same diagnostics engine and lockstep MCU. Engineers gain roughly 30% PCB area savings versus a discrete two-IC architecture.
推荐
Steering-Wheel Airbag Module
Steering-wheel airbag modules have to fit the inflate volume, the horn contact, and the satellite sensors in a tightly curved space. The L9678PTR-S at 64-LQFP 10x10 mm lets the airbag ECU PCB ride behind the horn contact with the integrated PSI5 interface for satellite crash sensors and the integrated battery cut-off for the inflator squib. Its -40 C to +95 C automotive Grade 1 qualification covers both the cold-soak at -40 C and the 95 C dashboard heat-soak. Integrated loop diagnostics also reduce the test-cycle time on the steering-wheel assembly line.
推荐
Emerging-Market Airbag Restraint ECU
Emerging-market restraint ECUs are cost-sensitive designs that need AEC-Q100 + ISO 26262 ASIL-D but cannot afford multi-IC architectures. The L9678PTR-S targets this exact use case by integrating the deployable driver, PSI5 receiver, battery cut-off, watchdog, and safing engine into a single 64-LQFP. Engineers can ship a complete 4-squib + 10-satellite airbag ECU with one main IC plus a host MCU. This integration directly lowers the BOM and the latent-failure rate, which is the dominant cost driver for tier-1 suppliers in cost-sensitive airbag programs.
推荐
推荐产品汇总
工程参考数据： L9678PTR-S ——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 | L9678PTR | L9678TR-S |
|---|---|---|---|
| Package | 64-LQFP (10x10 mm) | 64-LQFP (10x10 mm) - same | 64-LQFP (10x10 mm) - same |
| Brand | STMicroelectronics | STMicroelectronics - same | STMicroelectronics - same |
| Operating Voltage Range | 6 V to 18 V (40 V load-dump) | 6 V to 18 V (40 V load-dump) | 6 V to 18 V (40 V load-dump) |
| Battery Cut-Off Switch | Integrated solid-state | External FET required | Integrated solid-state |
| Deployable Channels | 2 HS + 4 LS = 6 channels | 2 HS + 4 LS = 6 channels | 2 HS + 4 LS = 6 channels |
| PSI5 Channels | 2 (up to 10 satellites) | 2 (up to 10 satellites) | 2 (up to 10 satellites) |
| Internal MCU | Dual ARM Cortex-M0 lockstep | Dual ARM Cortex-M0 lockstep | Dual ARM Cortex-M0 lockstep |
| AEC-Q100 Grade | Grade 1 (-40 C to +95 C) | Grade 1 (-40 C to +95 C) | Grade 1 (-40 C to +95 C) |
| Unit Price (qty 1000) | $3.95 | $3.65 (est.) | $4.10 (est.) |
关键差异点
- Integrated battery cut-off switch reduces BOM and PCB area （对比 L9678PTR)
- AEC-Q100 + ISO 26262 ASIL-D evidence package included （对比 L9678TR-S)
- PSI5 host supports 10 satellites per channel （对比 L9678PTR)
设计说明
Estimated: in a worst-case deployment event the L9678PTR-S can source roughly 1.2 A into the squib load for 1.5 ms with a 24 V VBAT. Using the 64-LQFP junction-to-ambient thermal resistance of approximately 35 C/W on a 4-layer JEDEC PCB, a single 1.5 ms pulse raises the junction by about 2 C above ambient, which is well within the 150 C automotive transient limit. Continuous deployment-loop diagnostics and watchdog activity add a quiescent dissipation of roughly 200 mW, giving about 7 C of steady-state rise at 25 C ambient. For under-dash mounting, provision a 1 square inch copper pour tied to the exposed pad.
Place the 100 nF VBAT decoupling capacitor within 2 mm of the VBAT pin and the 10 uF bulk capacitor on the same node. The PSI5 lines require series DC blocking capacitors (typically 1 nF to 10 nF X7R 50 V) and a TVS diode per channel to satisfy IEC 62228 pulse and ESD requirements. The exposed thermal pad must be soldered to a contiguous ground copper pour with at least 8 thermal vias to the inner ground plane for heat extraction.
Do not exceed the 40 V transient load-dump rating on VBAT - add a 36 V bidirectional TVS (e.g. SMBJ36CA) close to the connector. The SPI bus is not 5 V tolerant on the host side; ensure the external host MCU operates at 3.3 V or use an ISO7761 isolator with level shifting. Do not leave the watchdog-disable pin floating; tie it to VCC3V3 through a 10 kohm resistor if unused. PSI5 satellite addressing requires the satellite ID to be configured in the deployment script before deployment events will fire.
合规信息
AEC-Q100 Grade 1 qualified per ST automotive product family page. ISO 26262 ASIL-D capable per ST Safety Kit documentation. RoHS and REACH compliant per DigiKey product listing.
