L9974 - Automotive Dual H-Bridge Driver | STMicroelectronics
MPN： L9974 ✓ 啟用中L9974 概覽
A dual H-bridge driver is a power management IC that controls the direction and speed of DC motors by selectively switching four transistors per bridge. It sits within the motor driver hierarchy: dual H-bridge driver -> motor driver -> power management IC -> semiconductor. This architecture allows bidirectional current flow through the motor, enabling forward, reverse, and braking operations. The L9974 is specifically optimized for automotive environments, meeting AEC-Q100 Grade 1 requirements for operation from -40°C to +150°C.
Key features include a low quiescent current of 50 µA in standby mode, SPI interface for diagnostics and control, and integrated protection features such as overcurrent, overtemperature, and undervoltage lockout. The device also provides a current sense output for closed-loop motor control, enabling precise torque and speed regulation. The SPI interface allows real-time monitoring of fault conditions and configuration of the driver parameters, making it suitable for advanced automotive body control modules.
The L9974 utilizes a smart power technology that combines CMOS control logic with high-voltage power MOSFETs on a single die. This integration reduces external component count and improves reliability. The PowerSO-20 package offers a thermal resistance of 35°C/W, allowing efficient heat dissipation in high-current applications. The device is designed to withstand load dump and reverse battery conditions, ensuring robust operation in harsh automotive environments.
Typical applications include automotive HVAC actuators, headlamp leveling, mirror adjustment, and seat positioning systems. The dual H-bridge configuration allows independent control of two motors, reducing board space and system cost. The SPI interface simplifies wiring and enables advanced diagnostic features required by modern vehicle architectures.
When designing with the L9974, ensure proper PCB layout with adequate copper area for thermal management. The exposed pad must be soldered to a thermal via array to achieve the specified thermal performance. Additionally, place a 100 nF ceramic capacitor close to each supply pin to suppress high-frequency noise and ensure stable operation.
直接替換替代品，適用於 L9974 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
L9974A
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
L9942
⚡ 相同封裝 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →DRV8801
⚡ 相同封裝 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
L9974 最大額定值與電氣特性
| Supply Voltage Range | 5.5 V to 36 V |
| Output Current (Continuous) | 1.2 A per channel |
| Output Current (Peak) | 2 A per channel |
| Number of H-Bridges | 2 |
| Control Interface | SPI |
| Quiescent Current (Standby) | 50 µA |
| 工作溫度範圍 | -40°C to +150°C |
| 封裝 | PowerSO-20 |
| 安裝類型 | Surface Mount |
| 熱阻，接面至環境 | 35 °C/W |
| 過電流保護 | Yes |
| Overtemperature Protection | Yes |
| Undervoltage Lockout | Yes |
| Current Sense Output | Yes |
| AEC-Q100 Grade | Grade 1 |
| RoHS 狀態 | Compliant |
L9974 腳位配置
| 腳位 1 | OUT1 — Motor output 1 |
| 腳位 2 | OUT2 — Motor output 2 |
| 腳位 3 | VS — Supply voltage |
| 腳位 4 | GND — Ground |
| 腳位 5 | OUT3 — Motor output 3 |
| 腳位 6 | OUT4 — Motor output 4 |
| 腳位 7 | CS — Current sense output |
| 腳位 8 | SCK — SPI clock |
| 腳位 9 | SDI — SPI data input |
| 腳位 10 | SDO — SPI data output |
| 腳位 11 | CSN — SPI chip select (active low) |
| 腳位 12 | RST — Reset (active low) |
| 腳位 13 | IN1 — Control input 1 |
| 腳位 14 | IN2 — Control input 2 |
| 腳位 15 | IN3 — Control input 3 |
| 腳位 16 | IN4 — Control input 4 |
| 腳位 17 | VDD — Logic supply voltage |
| 腳位 18 | GND — Ground |
| 腳位 19 | VS — Supply voltage |
| 腳位 20 | GND — Ground |
典型應用
L9974 適用於 6 應用s: Automotive HVAC Actuators, Headlamp Leveling Systems, Mirror Adjustment, Seat Positioning Systems, Industrial Automation, Robotics.
Automotive HVAC Actuators
The L9974 drives the DC motors used in HVAC flap actuators, providing precise control of air flow direction and temperature. Its dual H-bridge allows independent control of two actuators, reducing component count. The SPI interface enables diagnostic feedback for fault detection, and the wide supply voltage range accommodates battery voltage variations. The low quiescent current is beneficial for always-on systems. The device's thermal performance ensures reliable operation in the high-temperature environment near the HVAC unit.
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Headlamp Leveling Systems
The L9974 controls the stepper motors used in headlamp leveling systems, ensuring proper beam alignment. Its dual H-bridge can drive a bipolar stepper motor with precise current control via SPI. The device's automotive qualification and wide temperature range make it suitable for under-hood mounting. The current sense output allows closed-loop control for accurate positioning. The robust protection features prevent damage from motor faults.
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Mirror Adjustment
The L9974 drives the DC motors for electric mirror adjustment, providing smooth and precise movement. Its dual H-bridge allows independent control of horizontal and vertical motors. The SPI interface enables simple control and diagnostics. The low standby current is ideal for applications that are frequently in standby. The device's small footprint and thermal efficiency are advantageous for space-constrained mirror modules.
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Seat Positioning Systems
The L9974 drives the multiple DC motors used in seat positioning, enabling adjustments for comfort and safety. Its dual H-bridge can control two motors simultaneously, reducing the number of drivers needed. The SPI interface allows coordination of multiple motors and diagnostic monitoring. The high peak current capability supports motor startup. The device's automotive grade ensures reliability in the demanding environment of a vehicle seat.
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Industrial Automation
The L9974 can be used in industrial automation for controlling small DC motors in valves, pumps, and actuators. Its wide supply voltage range and robust protection features make it suitable for industrial environments. The SPI interface allows integration with PLCs and industrial networks. The device's thermal performance enables continuous operation in high-temperature settings. The dual H-bridge configuration is ideal for applications requiring bidirectional control.
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Robotics
The L9974 drives the DC motors in small robots, providing precise speed and direction control. Its dual H-bridge allows control of two motors for differential drive. The SPI interface enables high-speed communication with the robot's controller. The low quiescent current is beneficial for battery-powered robots. The device's compact package and thermal efficiency are ideal for space-constrained robot designs.
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推薦產品摘要
工程參考資料，適用於 L9974 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | L9974A | L9942 | DRV8801 |
|---|---|---|---|---|
| Package | PowerSO-20 | PowerSO-20 | PowerSO-20 | PowerSO-20 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Number of H-Bridges | 2 | 2 | 1 | 1 |
| Supply Voltage Range | 5.5V to 36V | 5.5V to 36V | 5.5V to 36V | 8V to 36V |
| Output Current (Continuous) | 1.2A per channel | 1.2A per channel | 1.2A | 1.5A |
| Control Interface | SPI | SPI | SPI | PWM |
| Quiescent Current (Standby) | 50 µA | 50 µA | 50 µA | 1 mA |
| AEC-Q100 Grade | Grade 1 | Grade 1 | Grade 1 | Not qualified |
主要差異化特點
- Dual H-bridge in a single package (對比L9942)
- SPI interface for diagnostics (對比DRV8801)
- AEC-Q100 Grade 1 qualification (對比DRV8801)
設計說明
The PowerSO-20 package has a thermal resistance of 35°C/W. For continuous operation at 1.2A per channel with a 12V supply and 6V motor voltage, power dissipation is approximately 7.2W. Ensure adequate PCB copper area and thermal vias under the exposed pad to keep junction temperature below 150°C.
Place a 100 nF ceramic capacitor close to each VS pin and a 10 µF electrolytic capacitor at the main supply input. The exposed pad must be soldered to a thermal via array for optimal heat transfer. Keep SPI traces short and shielded to minimize noise.
Do not exceed the absolute maximum supply voltage of 40V. Ensure the logic supply (VDD) is within the specified range to avoid undervoltage lockout. The current sense output should be connected to an ADC with appropriate scaling to avoid saturation.
合規資訊
RoHS compliant per STMicroelectronics product page. AEC-Q100 Grade 1 qualified.