L99MH98 Octal Automotive Gate Driver with Patented Features
STMicroelectronics has introduced the L99MH98, an innovative 8-channel gate driver designed to simplify automotive motor-drive designs while reducing power dissipation and overall bill of materials (BOM) costs. This cutting-edge solution is particularly suited for applications like powered seats, sunroofs, window lifters, sliding doors, and trunk or tailgate mechanisms.
Advanced Motor Control Without Shunt Resistors
The L99MH98 leverages patented technologies to eliminate the need for sensing resistors, traditionally used in motor control designs. Instead, the device employs an indirect current measurement method, calculating the drain current of each MOSFET by combining the measured drain-source voltage (VDS) with temperature-predicted RDS(on). This method reduces power dissipation, enhances efficiency, and lowers costs. Each system undergoes factory calibration to determine nominal RDS(on) values, allowing precise predictions using MOSFET resistance-versus-temperature curves.
Versatile Performance Across a Range of Applications
Capable of driving up to four external full bridges, eight half bridges, or single high-side/low-side configurations, the L99MH98 is ideal for a variety of automotive actuators, including seatbelt pretensioners, pumps, and heaters. The device also features an integrated charge pump to control reverse-battery protection MOSFETs, further enhancing its versatility.
The driver supports both logic-level and standard-level MOSFETs, with programmable gate current capabilities of up to 120mA, making it suitable for driving large arrays of external MOSFETs. Additionally, its three-stage gate control applies the gate signal in three steps to minimize electromagnetic emissions, ensuring compliance with stringent automotive standards.
Enhanced Reliability Through Multi-Failsafe Functionality
To address fault conditions, the L99MH98 incorporates a programmable multi-failsafe feature, another patented innovation from STMicroelectronics. This function improves system reliability by selectively turning off individual bridges in the event of a fault, while allowing unaffected bridges to continue operating. The system detects various fault conditions, including supply overvoltage, thermal warnings, and VDS-monitoring failures, and responds by disabling specific functions such as diagnostics, watchdog, or the charge pump as needed.
Meeting Industry Standards and Functional Safety Requirements
The L99MH98 is AEC-Q100 qualified and meets ISO 26262 requirements for functional safety up to Automotive Safety Integrity Level (ASIL) B, making it a dependable choice for safety-critical applications in automotive systems.
Availability and Pricing
The L99MH98 is available now in a compact VFQFN48L package with wettable flanks and an exposed underside cooling pad. Pricing starts at $2.44 for orders of 1,000 pieces.
For more details, visit: STMicroelectronics L99MH98 Octal Gate Driver.
