L9637D - ISO 9141 Automotive Bus Transceiver | STMicroelectronics
料号： L9637D ✓ 量产中L9637D 概述
An automotive bus transceiver is an interface integrated circuit that combines bus-driver and receiver functions with the electrical protection and signal conditioning required to connect a host controller to a vehicle network. The L9637 belongs to the broader ISO 9141 interface transceiver hierarchy, where automotive diagnostics, K-line communication, and bidirectional serial links are the primary application domains.
Key features include standard ISO 9141-compatible interface functions, bidirectional serial communication, reverse-battery protection, and a wide operating supply range. The monolithic design reduces the number of discrete components associated with a vehicle diagnostic interface. Its 8-pin SOIC format also supports compact surface-mount layouts and automated electronic assembly.
The L9637 is intended for bidirectional communication between an automotive diagnostic tool, ECU, or other K-line interface and its associated controller. A 4.5 V minimum operating supply permits use in 5 V-class electronic systems, while operation up to 36 V provides headroom for automotive load-dump environments. The specified 40 V transient capability and -24 V reverse-supply protection are particularly important in vehicle electrical systems where wiring transients and accidental battery reversal can occur.
Typical applications include ISO 9141 diagnostic interfaces, automotive ECU test equipment, bidirectional K-line links, vehicle communication modules, and service-bus diagnostic systems. The device is also suitable for industrial communication equipment that must reproduce an ISO 9141 bus interface. System-level suitability still depends on the exact bus waveform, bus speed, external resistors, connector protection, and ECU timing implemented around the transceiver.
For PCB design, keep the bus connection and supply-return paths short, follow the manufacturer application schematic for external components, and place protection structures close to the vehicle connector. Designers should verify transient, ground-offset, and reverse-polarity conditions at the system level rather than relying only on the IC ratings. The available verified data does not provide the detailed pin table, temperature range, current limits, or timing characteristics.
This page consolidates the verified STMicroelectronics product description, supply-protection limits, package information, ordering references, and distributor links into one engineering-oriented source. It also documents where pricing, pin-level, lifecycle, and drop-in replacement evidence remains unavailable, preventing unsupported claims from being presented as verified fact.
直接替换替代料： L9637D ——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： L9637D （相同外形与封装尺寸） ——差异在于 Package.
该产品暂无直接替换替代料。
请求替代料L9637D 规格参数
| Product Type | Monolithic ISO 9141-compatible bus transceiver |
| Interface Standard | ISO 9141 |
| 工作电源电压 | 4.5 V to 36 V |
| Transient Supply Voltage | 40 V |
| Reverse Supply Protection | Down to VS = -24 V |
| Signal Direction | Bidirectional serial communication |
| Primary Application | Automotive diagnostic interfaces |
| 封装 | 8-pin SOIC, 0.154 inch (3.90 mm) width |
| 安装类型 | Surface mount |
| Order Code Shown | L9637D |
| Tape-and-Reel Order Code | L9637D013TR |
| Automotive-Grade Order Code | E-L9637D |
| Automotive-Grade Tape-and-Reel Order Code | E-L9637D013TR |
| Transceiver Count | 1 transceiver |
L9637D 8-pin soic, 0.154 inch (3.90 mm) width 引脚配置指南
L9637D（8-pin soic, 0.154 inch (3.90 mm) width 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： L9637D.
请参阅 数据手册 以查看完整引脚配置。
典型应用
L9637D 适用于 6 应用s: Automotive Diagnostic Interfaces, ECU Bidirectional Communication, K-Line Diagnostic Test Equipment, Vehicle Communication Modules, Industrial ISO 9141 Equipment, Automotive Production and End-of-Line Test.
Automotive Diagnostic Interfaces
The L9637D fits an ISO 9141 diagnostic interface because it provides the bidirectional bus-driver and receiver functions required to communicate between a diagnostic controller and vehicle electronics. Its verified 4.5 V to 36 V operating supply, 40 V transient tolerance, and reverse-supply protection to -24 V address the electrical disturbances found in vehicle wiring environments. Place the transceiver between the host controller and K-line connection, using the manufacturer’s reference circuit for external resistors and protection components. This implementation preserves a defined physical interface while allowing the surrounding microcontroller or diagnostic tool to manage message timing and vehicle addressing.
推荐
ECU Bidirectional Communication
The L9637D can serve as the physical-layer interface in an electronic control unit that exchanges diagnostic or service information over an ISO 9141-compatible bus. Its monolithic transceiver implementation reduces the number of separate driver and receiver blocks, while bidirectional operation supports command and response traffic on the same connection. The 4.5 V minimum supply is useful for low-voltage controller environments, and the 36 V maximum operating voltage provides automotive supply headroom. Engineers should verify timing against the specific ECU protocol and keep the bus trace short, with connector-side surge protection placed close to the entry point.
推荐
K-Line Diagnostic Test Equipment
The L9637D is suitable for service equipment that connects a PC, handheld tester, or embedded controller to a vehicle’s ISO 9141 diagnostic connection. Because it combines bidirectional transmit and receive functions, the same interface can support request and response traffic without separate external line-driver circuits. The device’s 4.5 V to 36 V operating range and 40 V transient capability help protect the tester electronics when connected to an automotive harness. The implementation should include an appropriate connector, input protection, and reference-ground strategy because transceiver specifications alone do not eliminate wiring-induced faults.
推荐
Vehicle Communication Modules
The L9637D can provide the ISO 9141 physical interface within a gateway, communication adapter, or body-control module that exchanges diagnostic data with other vehicle systems. The monolithic 8-pin SOIC implementation supports compact surface-mount construction, while the wide supply range and reverse-polarity protection improve suitability for automotive electrical environments. To obtain measurable system benefits, place the IC near the protected connector and route the bus away from switching nodes and sensitive analog sections. Firmware must also implement the required baud timing and message-handshake behavior for the target vehicle network.
推荐
Industrial ISO 9141 Equipment
The L9637D can also be used in industrial test or communication equipment that must emulate an ISO 9141 automotive diagnostic link. Its bidirectional interface functions allow equipment to send requests and receive responses over one bus, while the 4.5 V to 36 V supply range accommodates both low-voltage logic rails and higher automotive-derived supplies. The key engineering consideration is reproducing the original bus waveform and threshold behavior rather than treating ISO 9141 as a generic serial interface. Validation should therefore include timing, dominance, receiver response, and fault-recovery tests against the vehicle specification and the STMicroelectronics test conditions.
推荐
Automotive Production and End-of-Line Test
The L9637D supports automotive production and end-of-line test systems that need to verify diagnostic communication on an assembled vehicle or ECU. Bidirectional communication permits the tester to issue diagnostic commands and check the ECU response through the same standardized bus interface. Its 4.5 V to 36 V operating envelope, transient tolerance, and reverse-battery protection help the interface withstand industrial and vehicle electrical conditions encountered during service and production. For production stability, provide a defined connector and harness, isolate the bus from test-rack ground differences, and confirm every selected production grade and order code against current STMicroelectronics documentation.
推荐
推荐产品汇总
工程参考数据： L9637D ——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 |
|---|---|
| Package | 8-pin SOIC, 0.154 inch (3.90 mm) width |
| Brand | STMicroelectronics |
| Interface Standard | ISO 9141 |
| Operating Supply Voltage | 4.5 V to 36 V |
| Transient Supply Voltage | 40 V |
| Reverse Supply Protection | Down to VS = -24 V |
| Communication Direction | Bidirectional |
| Application | Automotive diagnostic communication |
关键差异点
- Verified automotive electrical protection envelope （对比 No verified drop-in alternative was identified)
- Bidirectional ISO 9141 interface in one monolithic IC （对比 No verified drop-in alternative was identified)
- Direct manufacturer-supported source （对比 Unverified marketplace equivalents)
设计说明
Follow the manufacturer reference schematic for the L9637D external components and connect the bus and supply returns with short traces. Keep the IC and its input/output network close to the vehicle connector where possible. The supplied verified data does not identify the pin functions or required resistor values, so engineers should obtain those details directly from the official STMicroelectronics datasheet before finalizing the layout.
The verified operating range is 4.5 V to 36 V, with transient tolerance to 40 V and reverse-supply protection to -24 V. These ratings do not eliminate all automotive electrical transients, so external protection may still be required after the connector. Place surge-protection components close to the harness entry and verify their voltage and pulse ratings against the vehicle transient specification.
Keep the sensitive transceiver and bus nodes away from switching-regulator inductors, high-current motor traces, and clocks with fast edges. Use a continuous ground reference beneath the IC and provide a low-impedance return path to the bus interface. Although the L9637D is a relatively slow diagnostic transceiver, poor grounding or long unprotected wiring can still produce false transitions and compromise communication reliability.
合规信息
The supplied verified excerpts identify automotive diagnostics and list E-L9637D ordering codes but do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. Confirm these attributes on the current STMicroelectronics product page and the latest declarations before release.
