ST's Configurable Automotive Low-Dropout Regulator Provides Diagnostics for Functional Safety

     ST's L99VR01 AEC-Q100 qualified low-dropout linear regulator features eight selectable fixed output voltages, functional safety diagnostics, and excellent thermal protection to help simplify system design, facilitate inventory management, and is suitable for a variety of automotive applications.

     With a maximum output current of 200mA, the regulator can drive loads such as body control modules, junction boxes, instrument panels, sunroof controllers, keyless entry controllers and sensors. The output voltage can be set to 0.8V, 1.2V, 1.5V, 1.8V, 2.5V, 2.8V, 3.3V or 5V through three external chip select pins, and the output voltage accuracy is better than that of an external voltage divider. within ±2% of the voltage.

     There are currently two types of products. The L99VR01S is available in a standard SO-8 package with enable and reset pins, and safety features such as fast output discharge, undervoltage lockout (UVLO), thermal shutdown, and short-circuit protection. Quiescent current drops to 1μA when disabled. Operating temperature Range -40°C to 150°C.

     L99VR01J adopts PowerSSO-12 package. Compared with the previous model, it adds short-circuit current limit setting, high temperature warning and output overvoltage status indication functions, and has a built-in programmable watchdog to verify whether the main control microcontroller is operating normally. The L99VR01J operates over a wider junction temperature range of -40°C to 175°C.

     The input voltage range of the two products is 2.15V to 28V, which can be directly connected to the car battery voltage VBAT, or connected to the back of the regulated power supply to adjust the output voltage of the regulated power supply. By integrating output overvoltage monitoring on-chip, the new regulator provides continuous load protection. This diagnostic function can simplify the design of functional safety-related applications and help users meet the requirements of the ISO 26262 ASIL functional safety standard, and provide corresponding supporting documents if required by users.