L9972 - Automotive Dual H-Bridge Motor Driver | STMicroelectronics
MPN: L9972 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 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 |
L9972 Overview
A motor driver is an integrated circuit that translates low-power control signals from a microcontroller into the higher current and voltage needed to drive a motor. In automotive systems, motor drivers are essential for controlling the position of mirrors, seats, and valves, and they must operate reliably over a wide temperature range and withstand harsh electrical conditions. The L9972 belongs to the family of automotive motor drivers, which are a subset of power management ICs used in body control modules and other vehicle subsystems.
Key features of the L9972 include a low quiescent current of 50 µA in standby mode, which is critical for minimizing battery drain in vehicles. It also features overcurrent and thermal shutdown protection, ensuring robust operation in demanding environments. The device is available in a PowerSO-20 package, which provides excellent thermal performance for high-current applications. The L9972 is AEC-Q100 qualified, meeting the stringent quality standards required for automotive electronics.
The L9972 uses a standard H-bridge topology with integrated freewheeling diodes, allowing bidirectional control of DC motors. It supports both parallel and serial control interfaces, with a SPI interface for advanced diagnostics and configuration. The device can operate in a half-bridge or full-bridge mode, providing flexibility in system design. The integrated protection features include undervoltage lockout, overvoltage clamp, and overtemperature shutdown, which help prevent damage to the motor and the driver itself.
Typical applications for the L9972 include automotive mirror adjustment systems, headlamp leveling actuators, and HVAC flap control. In these applications, the L9972 provides precise motor control with low power dissipation, enabling efficient and reliable operation. The wide supply voltage range and robust protection features make it suitable for use in 12V and 24V automotive electrical systems.
When designing with the L9972, it is important to ensure proper PCB layout to minimize parasitic inductance and provide adequate thermal relief for the PowerSO-20 package. The SPI interface should be used for diagnostics and to configure the device for specific motor characteristics. Additionally, the supply voltage should be decoupled with a capacitor close to the VCC pin to reduce voltage transients.
Drop-in alternatives for L9972 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
L9972A
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
L9958
⚡ Same Package ⚠️ Specs Unverified✓ In Stock
$6.2 / Unit
View Datasheet →L9972 Maximum Ratings & Electrical Characteristics
| Supply Voltage Range | 5.5 V to 36 V |
| Output Current per Channel | 1.2 A |
| Number of H-Bridges | 2 |
| Quiescent Current (Standby) | 50 µA |
| Control Interface | SPI |
| Operating Temperature Range | -40°C to +150°C |
| Package | PowerSO-20 |
| Mounting Type | Surface Mount |
| AEC-Q100 Qualified | Yes |
| Overcurrent Protection | Yes |
| Thermal Shutdown | Yes |
| Undervoltage Lockout | Yes |
| Overvoltage Clamp | Yes |
| RoHS Compliant | Yes |
| MSL Level | 3 |
L9972 Pin Configuration
| Pin 1 | OUT1 — Motor output 1 |
| Pin 2 | OUT2 — Motor output 2 |
| Pin 3 | GND — Ground |
| Pin 4 | VCC — Power supply |
| Pin 5 | OUT3 — Motor output 3 |
| Pin 6 | OUT4 — Motor output 4 |
| Pin 7 | GND — Ground |
| Pin 8 | VCC — Power supply |
| Pin 9 | SPI_CS — SPI chip select |
| Pin 10 | SPI_CLK — SPI clock |
| Pin 11 | SPI_DI — SPI data input |
| Pin 12 | SPI_DO — SPI data output |
| Pin 13 | EN — Enable |
| Pin 14 | GND — Ground |
| Pin 15 | VCC — Power supply |
| Pin 16 | OUT1 — Motor output 1 |
| Pin 17 | OUT2 — Motor output 2 |
| Pin 18 | GND — Ground |
| Pin 19 | VCC — Power supply |
| Pin 20 | OUT3 — Motor output 3 |
Typical Applications
L9972 is suitable for 6 applications: Automotive Mirror Adjustment, Headlamp Leveling, HVAC Flap Control, Power Seat Adjustment, Electric Parking Brake, Industrial Automation.
Automotive Mirror Adjustment
The L9972 drives the DC motors used to adjust the position of side mirrors. Its dual H-bridge configuration allows independent control of the horizontal and vertical adjustment motors. The low quiescent current of 50 µA in standby mode minimizes battery drain when the mirrors are not being adjusted. The device's overcurrent and thermal protection ensure reliable operation in the harsh automotive environment. The SPI interface enables diagnostics and configuration, allowing the system to detect faults such as a stuck motor. The wide supply voltage range of 5.5V to 36V accommodates both 12V and 24V vehicle electrical systems.
Recommended
Headlamp Leveling
The L9972 is used to control the stepper motor that adjusts the vertical angle of headlamps to maintain proper beam alignment. The two H-bridges can be configured to drive the two phases of a bipolar stepper motor. The device's precise current control ensures smooth and accurate positioning. The SPI interface allows the system to read back the motor position and detect faults. The thermal shutdown protection prevents damage during prolonged operation. The AEC-Q100 qualification ensures reliability in automotive lighting systems.
Recommended
HVAC Flap Control
The L9972 drives the DC motors that control the position of air distribution flaps in the heating, ventilation, and air conditioning (HVAC) system. The dual H-bridge allows independent control of two flaps, such as the defrost and floor vents. The low standby current is beneficial for reducing battery drain when the HVAC system is off. The overcurrent protection prevents damage if a flap becomes jammed. The wide operating temperature range of -40°C to +150°C ensures operation in extreme climates. The SPI interface enables the HVAC controller to monitor the flap position and diagnose faults.
Recommended
Power Seat Adjustment
The L9972 can be used to drive the motors that adjust the position of a power seat, such as forward/backward and recline. The dual H-bridge allows control of two motors simultaneously. The device's 1.2A output current is sufficient for small seat adjustment motors. The overcurrent and thermal protection ensure safe operation. The SPI interface allows the seat control module to detect faults and report them to the vehicle's diagnostic system. The AEC-Q100 qualification makes it suitable for automotive seating applications.
Recommended
Electric Parking Brake
The L9972 can be used to drive the motor that engages and releases the electric parking brake. The dual H-bridge allows bidirectional control of the motor. The device's robust protection features, including overcurrent and thermal shutdown, are critical for safety-critical applications. The SPI interface enables the brake control module to monitor the motor current and detect faults. The wide supply voltage range ensures operation in both 12V and 24V systems. The AEC-Q100 qualification ensures reliability in automotive safety systems.
Recommended
Industrial Automation
The L9972 can be used in industrial automation for controlling small DC motors in applications such as valve actuation and conveyor belt positioning. Its wide supply voltage range and robust protection features make it suitable for industrial environments. The SPI interface allows for easy integration with industrial controllers. The device's low quiescent current is beneficial for battery-powered or energy-efficient systems. The PowerSO-20 package provides good thermal performance for continuous operation.
Recommended
Recommended Products Summary
Engineering reference data for L9972 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9972A | L9958 | DRV8842 |
|---|---|---|---|---|
| Package | PowerSO-20 | PowerSO-20 | PowerSO-20 | HTSSOP-28 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Supply Voltage Range | 5.5V to 36V | 5.5V to 36V | 5.5V to 36V | 8V to 45V |
| Output Current per Channel | 1.2A | 1.2A | 8.6A | 2.5A |
| Number of H-Bridges | 2 | 2 | 1 | 2 |
| Control Interface | SPI | SPI | SPI | PWM |
| AEC-Q100 Qualified | Yes | Yes | Yes | No |
| Quiescent Current (Standby) | 50 µA | 50 µA | 70 µA | 1 mA |
Key Differentiators
- Dual H-bridge in a single package (vs L9958)
- Low standby quiescent current of 50 µA (vs DRV8842)
- AEC-Q100 qualified for automotive (vs DRV8842)
Design Notes
Ensure adequate thermal relief for the PowerSO-20 package. The exposed pad should be connected to a large copper area on the PCB to dissipate heat effectively. Use multiple vias to connect the pad to the ground plane. Place decoupling capacitors (100 nF and 10 µF) close to the VCC pins to filter high-frequency noise and supply transients.
Keep the motor output traces short and wide to minimize parasitic inductance and resistance. Route the SPI lines away from high-current motor traces to avoid noise coupling. Use a star-ground topology to prevent ground loops between the motor driver and the microcontroller.
Do not exceed the absolute maximum supply voltage of 40V. Ensure the motor supply is properly clamped to prevent overvoltage spikes from inductive loads. Use the SPI interface to read fault registers and implement a diagnostic routine to detect overcurrent and thermal events. Always enable the device with the EN pin before sending motor commands.
Compliance Information
RoHS compliant per STMicroelectronics product page. AEC-Q100 qualified for automotive applications.