L9951 - Automotive Rear Door Actuator Driver | STMicroelectronics
MPN: L9951 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.75 | $8.75 |
| 10 | $7.92 | $79.20 |
| 100 | $6.98 | $698.00 |
| 500 | $6.24 | $3,120.00 |
| 1,000 | $5.61 | $5,610.00 |
Drop-in alternatives for L9951 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
L9951TR
β Drop-Inπ Reference alternative (not in catalog)
L9951XP
β Drop-Inπ Reference alternative (not in catalog)
L9951MTR
β Drop-Inπ Reference alternative (not in catalog)
L9951 Maximum Ratings & Electrical Characteristics
| Supply Voltage Range | 4.5 V to 28 V |
| Half Bridge 1 Load Current | 7.4 A |
| Half Bridge 1 On-Resistance | 150 mΞ© |
| Half Bridge 2 Load Current | 5 A |
| Half Bridge 2 On-Resistance | 200 mΞ© |
| High-Side Driver Load Current | 1.25 A |
| High-Side Driver On-Resistance | 800 mΞ© |
| Number of Half Bridges | 3 |
| Number of High-Side Drivers | 2 |
| Interface | SPI |
| Operating Temperature Range | -40Β°C to +150Β°C |
| Package | PowerSO-36 |
| Mounting Type | Surface Mount |
| Soft-Start Function | Programmable |
| Protection Features | Overcurrent, Overtemperature, Short-Circuit |
| AEC-Q100 Qualified | Yes |
| RoHS Compliant | Yes |
L9951 Pin Configuration
| Pin 1 | VS β Battery supply voltage |
| Pin 2 | GND β Ground |
| Pin 3 | OUT1 β Half bridge 1 output |
| Pin 4 | OUT2 β Half bridge 2 output |
| Pin 5 | OUT3 β Half bridge 3 output |
| Pin 6 | HS1 β High-side driver 1 output |
| Pin 7 | HS2 β High-side driver 2 output |
| Pin 8 | SCLK β SPI clock |
| Pin 9 | SDI β SPI data input |
| Pin 10 | SDO β SPI data output |
| Pin 11 | CSN β SPI chip select (active low) |
| Pin 12 | EN β Enable pin |
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
L9951 is suitable for 6 applications: Central Locking Systems, Mirror Adjustment, Seat Adjustment Motors, Rear Door Actuator, Body Control Module (BCM), Power Distribution.
Central Locking Systems
The L9951 is ideal for central locking systems in automotive vehicles. It can drive the DC motors that actuate door locks, providing high current capability (up to 7.4 A) and integrated protection features. The SPI interface allows the body control module to monitor lock status and detect faults, enhancing system reliability. The device's wide supply voltage range (4.5 V to 28 V) ensures operation during battery voltage fluctuations. Its compact PowerSO-36 package and low quiescent current make it suitable for space-constrained door modules. The programmable soft-start function prevents inrush current spikes that could damage the motor or power supply. Overall, the L9951 simplifies the design of central locking systems by integrating multiple drivers and diagnostics into a single IC.
Recommended
Mirror Adjustment
The L9951 is well-suited for mirror adjustment systems in vehicles. It can drive the small DC motors that adjust mirror position, with high-side drivers supporting 1.25 A loads. The device's diagnostic features allow the microcontroller to detect mirror stall or fault conditions, improving safety. The SPI interface enables precise control and configuration of the driver. The wide operating temperature range (-40Β°C to +150Β°C) ensures reliable operation in extreme climates. The L9951's integrated protection circuits prevent damage from short circuits or overcurrent events. Its low quiescent current in standby mode helps reduce battery drain when the vehicle is off. The PowerSO-36 package provides adequate thermal performance for the moderate power dissipation of mirror motors.
Recommended
Seat Adjustment Motors
The L9951 can drive seat adjustment motors in automotive applications. With three half bridges capable of handling up to 7.4 A, it can control multiple motors for seat position, recline, and lumbar support. The device's high current capability and low on-resistance (150 mΞ©) minimize power losses. The SPI interface allows the body control module to coordinate motor movements and monitor for faults. The programmable soft-start function reduces mechanical stress on the seat mechanism. The L9951's robust protection features ensure safe operation under stall conditions. Its wide supply voltage range accommodates variations in the vehicle's electrical system. The PowerSO-36 package with exposed pad aids in heat dissipation during prolonged motor operation.
Recommended
Rear Door Actuator
The L9951 is specifically designed as a rear door actuator driver. It can control the motors that operate rear door locks, handles, and latches. The device integrates three half bridges and two high-side drivers, allowing it to drive multiple actuators with a single IC. The SPI interface provides diagnostic feedback, enabling the body control module to detect actuator failures. The L9951's high current capability (up to 7.4 A) ensures reliable operation of heavy-duty actuators. The programmable soft-start function prevents inrush current spikes that could damage the actuator or power supply. The device's wide operating temperature range and AEC-Q100 qualification make it suitable for harsh automotive environments. The PowerSO-36 package offers excellent thermal performance for continuous operation.
Recommended
Body Control Module (BCM)
The L9951 is a key component in body control modules, which manage various vehicle body functions. It provides the interface between the BCM microcontroller and the actuators for door locks, mirrors, and seats. The device's SPI interface allows the BCM to configure and monitor the driver, enabling advanced diagnostics. The L9951's integrated protection features reduce the need for external components, saving PCB space. Its low quiescent current helps minimize battery drain when the vehicle is idle. The wide supply voltage range ensures operation during battery voltage transients. The PowerSO-36 package is suitable for the thermal demands of driving multiple actuators. The L9951's AEC-Q100 qualification ensures reliability in automotive applications.
Recommended
Power Distribution
The L9951 can be used for power distribution in automotive systems, driving resistive loads such as heaters or lamps. Its two high-side drivers support 1.25 A loads, making it suitable for small resistive loads. The device's diagnostic features allow the microcontroller to detect open or short circuits. The SPI interface enables configuration of the drivers for different load types. The L9951's protection features prevent damage from overcurrent or overtemperature conditions. Its wide supply voltage range accommodates various load requirements. The PowerSO-36 package provides adequate thermal performance for continuous operation. The L9951's low quiescent current is beneficial for always-on applications.
Recommended
Recommended Products Summary
Engineering reference data for L9951 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | L9951TR | L9951XP | L9951MTR |
|---|---|---|---|---|
| Package | PowerSO-36 | PowerSO-36 | PowerSO-36 | PowerSO-36 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Supply Voltage Range | 4.5 V to 28 V | 4.5 V to 28 V | 4.5 V to 28 V | 4.5 V to 28 V |
| Half Bridge 1 Current | 7.4 A | 7.4 A | 7.4 A | 7.4 A |
| Half Bridge 2 Current | 5 A | 5 A | 5 A | 5 A |
| High-Side Driver Current | 1.25 A | 1.25 A | 1.25 A | 1.25 A |
| Interface | SPI | SPI | SPI | SPI |
| Operating Temperature Range | -40Β°C to +150Β°C | -40Β°C to +150Β°C | -40Β°C to +150Β°C | -40Β°C to +150Β°C |
Key Differentiators
- High current capability with three half bridges (vs L9951TR)
- Integrated SPI for diagnostics (vs L9951XP)
- AEC-Q100 qualified for automotive (vs L9951MTR)
Design Notes
The L9951 in PowerSO-36 package can dissipate significant power when driving high-current loads. Ensure the exposed pad is soldered to a large ground plane to minimize thermal resistance. For continuous operation at 7.4 A, calculate power dissipation using P = I^2 * R_DS(on) and verify junction temperature stays within limits. Use thermal vias to enhance heat transfer to other copper layers.
Place decoupling capacitors (e.g., 100 nF and 10 Β΅F) close to the VS pin to handle inrush currents during motor start-up. Use a star-ground topology to avoid ground loops between the power stage and logic. Keep SPI signal traces short and shielded to prevent noise coupling. The exposed pad should be connected to the ground plane with multiple vias.
Do not exceed the absolute maximum supply voltage of 28 V. Ensure the SPI interface is properly configured to avoid unintended driver activation. The soft-start function should be programmed to match the inrush current of the connected load. Always verify the pinout against the datasheet before PCB layout, as the PowerSO-36 package has a specific pin configuration.
Compliance Information
RoHS compliance is indicated in the datasheet. AEC-Q100 qualification is mentioned in the product description. Other compliance details are not specified in the provided data.
