L9974-TR - Automotive Quad Half-Bridge Driver | STMicroelectronics
MPN: L9974-TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.25 | $3.25 |
| 10 | $2.92 | $29.20 |
| 100 | $2.6 | $260.00 |
| 500 | $2.34 | $1,170.00 |
| 1,000 | $2.08 | $2,080.00 |
L9974-TR Overview
A half-bridge driver is a power management IC that controls the direction and speed of DC motors by selectively connecting the motor terminals to the supply or ground. In a full H-bridge configuration, two half-bridges are combined to drive a motor bidirectionally. The L9974-TR simplifies this by integrating four half-bridges, allowing control of two DC motors or one stepper motor with minimal external components. This category sits within the broader hierarchy of motor drivers, which are essential in automotive systems such as power windows, seat adjustment, and mirror positioning.
Key features of the L9974-TR include a low quiescent current of 10uA in standby mode, making it suitable for battery-powered automotive applications. It offers overcurrent, overtemperature, and short-circuit protection, ensuring robust operation in harsh environments. The device also features a serial peripheral interface (SPI) for advanced diagnostics and control, allowing the microcontroller to read fault status and configure output states. The PowerSO-20 package has a thermal resistance of 35 C/W, enabling efficient heat dissipation.
Technically, the L9974-TR uses a smart power technology that integrates CMOS control logic with high-current DMOS output stages. This architecture provides low on-resistance (0.5 ohm typical) and fast switching, reducing power losses. The SPI interface operates at up to 5 MHz, enabling real-time monitoring and control. The device is AEC-Q100 qualified, meeting the stringent reliability standards for automotive electronics.
Typical applications include automotive body control modules, DC motor drivers for power windows and mirrors, and industrial automation systems. The wide input voltage range and robust protection make it ideal for 12V and 24V systems. In a power window application, the L9974-TR drives the window motor bidirectionally, with the SPI providing diagnostic feedback for stall detection.
When designing with the L9974-TR, ensure proper PCB layout with adequate copper area for thermal dissipation. Place the supply decoupling capacitor close to the VCC pin to minimize voltage spikes during switching. The SPI lines should be kept short and shielded to avoid noise coupling.
Drop-in alternatives for L9974-TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with L9974-TR (same form factor and footprint) — differing in Operating Temperature Range.
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L9973-TR
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View Datasheet →L9974-TR Maximum Ratings & Electrical Characteristics
| Supply Voltage Range | 5.5 V to 36 V |
| Output Current per Channel | 1.2 A (continuous) |
| Number of Half-Bridges | 4 |
| On-Resistance (typical) | 0.5 ohm |
| Quiescent Current (standby) | 10 uA |
| SPI Interface | Yes, up to 5 MHz |
| Protection Features | Overcurrent, overtemperature, short-circuit |
| Operating Temperature Range | -40C to +150C |
| Package | PowerSO-20 |
| Mounting Type | Surface Mount |
| Thermal Resistance, Junction-to-Ambient | 35 C/W |
| AEC-Q100 Qualification | Yes |
| RoHS Status | Compliant |
| Output Type | Half-bridge |
| Control Interface | SPI |
L9974-TR Pin Configuration
| Pin 1 | OUT1 — Half-bridge 1 output |
| Pin 2 | OUT2 — Half-bridge 2 output |
| Pin 3 | GND — Ground |
| Pin 4 | OUT3 — Half-bridge 3 output |
| Pin 5 | OUT4 — Half-bridge 4 output |
| Pin 6 | VCC — Supply voltage |
| Pin 7 | GND — Ground |
| Pin 8 | SPI_CS — SPI chip select |
| Pin 9 | SPI_CLK — SPI clock |
| Pin 10 | SPI_MOSI — SPI data input |
| Pin 11 | SPI_MISO — SPI data output |
| Pin 12 | EN — Enable pin |
Typical Applications
L9974-TR is suitable for 6 applications: Automotive Power Windows, DC Motor Control in Industrial Automation, Stepper Motor Driver for 3D Printers, Automotive Mirror Adjustment, Battery-Powered Robotics, Industrial Valve Actuator.
Automotive Power Windows
The L9974-TR drives the window lift motor bidirectionally. Its 1.2A output current and 36V supply range handle the motor's inrush current. The SPI interface provides diagnostic feedback for stall detection, enabling anti-pinch functionality. The AEC-Q100 qualification ensures reliability in extreme temperatures.
Recommended
DC Motor Control in Industrial Automation
In industrial automation, the L9974-TR controls conveyor belt motors or actuator motors. Its wide supply range (5.5V to 36V) accommodates various industrial power rails. The overcurrent and overtemperature protection prevent damage during overloads. The low standby current reduces energy consumption in idle states.
Recommended
Stepper Motor Driver for 3D Printers
The L9974-TR can drive a bipolar stepper motor by using its four half-bridges. Each phase is controlled by a pair of half-bridges, allowing precise positioning. The SPI interface enables microstepping control. The thermal performance of the PowerSO-20 package supports continuous operation.
Recommended
Automotive Mirror Adjustment
The L9974-TR drives the mirror adjustment motors for horizontal and vertical movement. Its compact size and low quiescent current are ideal for body control modules. The SPI diagnostics allow the ECU to detect mirror position faults. The AEC-Q100 qualification ensures long-term reliability.
Recommended
Battery-Powered Robotics
In battery-powered robots, the L9974-TR drives two DC motors for locomotion. Its low standby current (10uA) extends battery life. The wide supply range allows operation from 2S LiPo batteries (7.4V) or 3S (11.1V). The protection features prevent motor stall damage.
Recommended
Industrial Valve Actuator
The L9974-TR controls the motor in a valve actuator, providing precise open/close control. Its SPI interface allows the controller to read position feedback. The overcurrent protection prevents damage if the valve jams. The wide temperature range (-40C to +150C) suits harsh industrial environments.
Recommended
Recommended Products Summary
Engineering reference data for L9974-TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9973-TR | DRV8804 |
|---|---|---|---|
| Package | PowerSO-20 | PowerSO-20 | HTSSOP-20 |
| Brand | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Number of Half-Bridges | 4 | 2 | 4 |
| Output Current per Channel | 1.2 A | 1.2 A | 1.5 A |
| Supply Voltage Range | 5.5V to 36V | 5.5V to 36V | 8.2V to 45V |
| On-Resistance | 0.5 ohm | 0.5 ohm | 0.35 ohm |
| SPI Interface | Yes | Yes | Yes |
| AEC-Q100 | Yes | Yes | No |
Key Differentiators
- Four half-bridges in one package (vs L9973-TR)
- AEC-Q100 qualified (vs DRV8804)
- Wide supply voltage range (vs DRV8804)
Design Notes
The PowerSO-20 package has a thermal resistance of 35 C/W. At 1.2A per channel with 0.5 ohm on-resistance, each channel dissipates 0.72W. With all four channels active, total dissipation is 2.88W, causing a 100C temperature rise. Ensure adequate PCB copper area or forced airflow for high-duty-cycle operation.
Place a 100nF ceramic capacitor close to the VCC pin and a 10uF electrolytic capacitor nearby to handle current transients. Keep SPI traces short and shielded to prevent noise coupling. Use a ground plane to minimize inductance.
Do not exceed the absolute maximum supply voltage of 40V. Ensure the SPI lines are not left floating during power-up; pull them to known states. The enable pin must be driven high to activate outputs; otherwise, outputs are high-impedance.
Compliance Information
RoHS compliant and AEC-Q100 qualified per STMicroelectronics datasheet. Halogen-free status not specified.