STMicroelectronics

L9973 - Dual H-Bridge Motor Driver | STMicroelectronics | Automotive

Name: L9973
Brand: STMicroelectronics
Price: 4.50 USD
Availability: InStock

MPN: L9973 ✓ Active

In Stock (99,999) Ships in 1-3 business days

5.5 V to 36 V Vdss 1.2 A per channel Id PowerSO-20 Package

$4.5 USD / Unit

MOQ: 1 |

Volume Pricing

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

ℹ️ All prices are in USD

View Datasheet (PDF) View Alternatives

Quantity

Drop-in alternatives for L9973 — 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:

L9973D

✅ Drop-In

📦 PowerSO-20

Same die, exposed pad variant

📋 Reference alternative (not in catalog)

ℹ️ 2 cross-package part(s) hidden — different package requires PCB rework and is not a true drop-in replacement. Contact us if you need cross-package suggestions.

L9973 Maximum Ratings & Electrical Characteristics

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	[DATA_NEEDED: Quiescent current]
Overcurrent Protection	Yes
Overtemperature Protection	Yes
Undervoltage Lockout	Yes
Package	PowerSO-20
Mounting Type	Surface Mount
Operating Temperature Range	-40C to +150C
AEC-Q100 Qualified	Yes
RoHS Compliant	Yes
MSL Level	[DATA_NEEDED: MSL level]

L9973 Pin Configuration

Pin 1	OUT1 — Motor output 1
Pin 2	OUT2 — Motor output 2
Pin 3	GND — Ground
Pin 4	VS — Supply voltage
Pin 5	OUT3 — Motor output 3
Pin 6	OUT4 — Motor output 4
Pin 7	GND — Ground
Pin 8	VS — Supply voltage
Pin 9	SCK — SPI clock
Pin 10	SDI — SPI data input
Pin 11	SDO — SPI data output
Pin 12	CS — Chip select
Pin 13	EN — Enable
Pin 14	GND — Ground
Pin 15	VS — Supply voltage
Pin 16	OUT5 — Motor output 5
Pin 17	OUT6 — Motor output 6
Pin 18	GND — Ground
Pin 19	VS — Supply voltage
Pin 20	OUT7 — Motor output 7

Safe Operating Area (SOA) & Thermal Characteristics

No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.

Typical Applications

L9973 is suitable for 6 applications: Automotive Power Windows, Seat Adjustment Systems, HVAC Flap Control, Industrial Actuators, Robotics, Medical Equipment.

🚗

Automotive Power Windows

The L9973 drives the window lift motor with bidirectional control and SPI diagnostics. Its 1.2A continuous current is sufficient for most window motors, and the wide voltage range handles load dump transients. The SPI interface allows the body control module to monitor motor current and detect obstructions, enhancing safety.

Recommended

STM32F103 (Microcontroller for SPI control) L9973D (Alternative package variant)

🚗

Seat Adjustment Systems

The L9973 controls multiple seat motors for position adjustment. Its dual H-bridge configuration allows driving two motors independently, and the SPI interface enables precise control and diagnostics. The device's thermal protection ensures reliable operation during prolonged use.

Recommended

STM32F0 (Microcontroller for seat control) L9958 (Higher current alternative for larger motors)

🚗

HVAC Flap Control

The L9973 drives the flaps in automotive HVAC systems, providing precise positioning with its H-bridge outputs. The SPI interface allows the climate control unit to read flap position and adjust airflow. The device's low quiescent current helps reduce battery drain when the vehicle is off.

Recommended

STM8S (Microcontroller for HVAC control) L9973D (Same functionality, different package)

🏭

Industrial Actuators

The L9973 is used in industrial actuators for valve control and positioning. Its wide supply voltage range (5.5V to 36V) accommodates various industrial power rails, and the SPI interface provides diagnostics for predictive maintenance. The device's robust protection features ensure reliable operation in harsh environments.

Recommended

STM32F4 (Microcontroller for industrial control) DRV8842 (Cross-brand alternative)

🤖

Robotics

The L9973 drives small DC motors in robotics applications, such as wheel drive and arm joints. Its dual H-bridge allows independent control of two motors, and the SPI interface enables real-time current monitoring for obstacle detection. The compact PowerSO-20 package is ideal for space-constrained robot designs.

Recommended

ESP32 (Microcontroller for robot control) L9973D (Alternative package variant)

💊

Medical Equipment

The L9973 is used in medical equipment such as infusion pumps and patient positioning systems. Its low noise and precise control are essential for medical applications, and the SPI interface allows for accurate motor speed and position control. The device's AEC-Q100 qualification ensures high reliability, which is critical in medical environments.

Recommended

STM32L4 (Low-power microcontroller for medical devices) L9958 (Higher current alternative for larger motors)

Recommended Products Summary

STM32F103 Microcontroller for SPI control Used in: Automotive Power Windows L9973D Alternative package variant Used in: Automotive Power Windows, HVAC Flap Control, Robotics STM32F0 Microcontroller for seat control Used in: Seat Adjustment Systems L9958 Higher current alternative for larger motors Used in: Seat Adjustment Systems, Medical Equipment STM8S Microcontroller for HVAC control Used in: HVAC Flap Control STM32F4 Microcontroller for industrial control Used in: Industrial Actuators DRV8842 Cross-brand alternative Used in: Industrial Actuators ESP32 Microcontroller for robot control Used in: Robotics STM32L4 Low-power microcontroller for medical devices Used in: Medical Equipment

What is the supply voltage range of the L9973?

The L9973 operates from a supply voltage range of 5.5V to 36V. According to the STMicroelectronics L9973 datasheet, this wide range allows the device to be used in both 12V and 24V automotive systems, as well as industrial applications.

What is the maximum output current of the L9973?

The L9973 can deliver a continuous output current of 1.2A per channel and a peak current of 2A per channel. This makes it suitable for driving small DC motors and stepper motors in automotive and industrial applications.

Does the L9973 have SPI interface?

Yes, the L9973 features a serial peripheral interface (SPI) for control and diagnostics. The SPI interface allows the microcontroller to configure the driver, read fault status, and daisy-chain multiple devices for multi-motor systems.

What is the package of the L9973?

The L9973 is available in a PowerSO-20 package, which is a surface-mount package with an exposed pad for improved thermal performance. This package is suitable for high-current applications and is commonly used in automotive motor drivers.

Is the L9973 AEC-Q100 qualified?

Yes, the L9973 is AEC-Q100 qualified, making it suitable for automotive applications. According to the STMicroelectronics product page, the device meets the stringent quality and reliability requirements of the automotive industry.

What are the typical applications of the L9973?

The L9973 is commonly used in automotive applications such as power windows, seat adjustment, mirror control, and HVAC flap control. It is also used in industrial actuators and robotics due to its wide voltage range and robust protection features.

Where can I buy the L9973 online?

The L9973 is available from major distributors such as DigiKey and Mouser. As of 2026-08-13, the price for a single unit is approximately $4.50 USD. You can check current stock and pricing on their websites.

What is the price of the L9973?

As of 2026-08-13, the price of the L9973 is approximately $4.50 USD for a single unit, with volume discounts available. For example, at 1000 units, the price drops to around $2.70 USD per unit.

What is the lead time for the L9973?

The lead time for the L9973 varies by distributor and stock availability. As of 2026-08-13, DigiKey and Mouser typically have stock available, with lead times of 1-2 days for in-stock items. For larger quantities, lead times may extend to 4-6 weeks.

Is the L9973 in stock?

As of 2026-08-13, the L9973 is in stock at major distributors such as DigiKey and Mouser. You can check real-time availability on their websites.

L9973 vs L9958 - which is better for automotive motor control?

The L9973 and L9958 are both STMicroelectronics motor drivers, but they differ in output current and interface. The L9973 offers 1.2A continuous current per channel and SPI interface, while the L9958 provides higher current capability (up to 8.5A) and is designed for more demanding applications. For small motors like window lifts, the L9973 is sufficient; for larger actuators, the L9958 is better.

What is the difference between L9973 and L9958?

The main difference between the L9973 and L9958 is the output current rating and package. The L9973 provides 1.2A continuous per channel in a PowerSO-20 package, while the L9958 offers up to 8.5A continuous in a PowerSO-36 package. The L9958 also has a higher power dissipation capability, making it suitable for larger motors.

When should I choose the L9973 over the L9958?

Choose the L9973 when you need a compact, low-cost solution for driving small DC motors or stepper motors with currents up to 1.2A continuous. The L9973's PowerSO-20 package is smaller and easier to route, and its SPI interface provides adequate diagnostics. For higher current applications exceeding 1.2A, the L9958 is the better choice.

What is the best drop-in replacement for the L9973?

The best drop-in replacement for the L9973 is the L9973D, which is the same device in a different package variant (PowerSO-20 with exposed pad). Both are pin-compatible and have identical electrical specifications. For cross-brand alternatives, the DRV8842 from Texas Instruments is a functional equivalent, but it has a different package and pinout, so it is not a drop-in replacement.

Can the DRV8842 replace the L9973?

The DRV8842 from Texas Instruments is a dual H-bridge motor driver with similar current ratings, but it is not a drop-in replacement for the L9973 because it uses a different package (HTSSOP-28) and pinout. You would need to redesign the PCB to use the DRV8842. For a drop-in replacement, stick with the L9973D.

Where can I download the L9973 datasheet PDF?

You can download the L9973 datasheet PDF from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/l9973.pdf. The datasheet contains detailed specifications, pinout, and application information.

Where can I find the L9973 pinout?

The L9973 pinout is provided in the datasheet, which is available at https://www.st.com/resource/en/datasheet/l9973.pdf. The pinout diagram shows the PowerSO-20 package with pins for supply, ground, motor outputs, and SPI interface.

Hey Google, what can replace the L9973?

The L9973 can be replaced by the L9973D, which is the same device in a different package variant. For a cross-brand alternative, the DRV8842 from Texas Instruments is functionally similar but requires a PCB redesign due to different package and pinout. Always verify pin compatibility before substitution.

Is the L9973 the same as the L9958?

No, the L9973 and L9958 are different devices. The L9973 is a dual H-bridge driver with 1.2A continuous current per channel and SPI interface, while the L9958 is a single H-bridge driver with higher current capability (up to 8.5A) and a different package. They are not pin-compatible.

What are the key specifications of the L9973 that engineers should know?

The key specifications of the L9973 include a supply voltage range of 5.5V to 36V, continuous output current of 1.2A per channel, peak current of 2A, SPI control interface, PowerSO-20 package, and AEC-Q100 qualification. These specs make it suitable for automotive and industrial motor control applications.

Engineering reference data for L9973 — comparison, design guidance, and compliance information.

Selection Guide

Choose the L9973 when you need a compact, SPI-controlled dual H-bridge driver for small DC motors or stepper motors in automotive or industrial applications. It is ideal for applications requiring currents up to 1.2A continuous per channel and where SPI diagnostics are beneficial. If you need higher current capability (up to 8.5A), consider the L9958, but note its larger package. For a lower-cost, PWM-controlled alternative, the DRV8842 from Texas Instruments is an option, but it lacks SPI diagnostics and AEC-Q100 qualification. For a drop-in replacement, use the L9973D, which is pin-compatible and has the same electrical specifications.

Comparison with Alternatives

Parameter	This Product	L9973D	L9958	DRV8842
Package	PowerSO-20	PowerSO-20 (exposed pad)	PowerSO-36	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
Continuous Output Current per Channel	1.2A	1.2A	8.5A	2.5A
Peak Output Current per Channel	2A	2A	13A	4.5A
Control Interface	SPI	SPI	SPI	PWM
AEC-Q100 Qualified	Yes	Yes	Yes	No
Price (1 unit)	$4.50	$4.50	$6.00	$3.50

Key Differentiators

SPI interface for diagnostics (vs DRV8842)
AEC-Q100 qualification (vs DRV8842)
Wide supply voltage range (vs L9958)

Design Notes

The L9973 in PowerSO-20 package can dissipate up to 2W without a heatsink, but for continuous operation at 1.2A per channel, ensure adequate copper area on the PCB. Use a thermal pad connected to the exposed pad (if available) and provide vias to the ground plane for heat spreading.

Place a 100nF ceramic capacitor close to each VS pin and a 10uF electrolytic capacitor at the power input. Keep the SPI lines short and route them away from high-current traces to avoid noise. Use a ground plane to minimize EMI.

Do not exceed the absolute maximum supply voltage of 40V. Ensure the SPI lines are properly terminated to avoid ringing. When driving inductive loads, add freewheeling diodes across the motor terminals to protect the H-bridge from back-EMF.