Automotive regulator with power-on-reset and MCU supervisory functions

September 23, 2015 // By Graham Prophet
For automotive applications, these 5V constant voltage regulators ICs incorporate system reset and functional safety protection features – a windowed watchdog monitor

TB9005FNG and TB9021FNG incorporate system reset functions for microcontrollers that contribute to improved safety in automotive systems. System reset functions include a window watchdog feature to aid the resetting of MCUs when an abnormal state is detected or a processor gets stuck in a loop. Further protection is provided by an over-current limiter. Both ICs are fabricated for low power consumption using Toshiba’s BiCD process.

TB9021FNG has a standby current of 30 µA (typ.) It also includes an output transistor that handles 0.2A of current and helps reduce the required number of external ICs. The TB9021FNG offers temperature detection and is durable against the reverse connection of Vcc and GND.

Delivering 1A or higher output current, in combination with an external power transistor, the TB9005FNG is suited for use in automotive applications that require high output current. The TB9005FNG has a standby current of 90 µA (typ.) and includes a current limiter which is adjustable with an external resistor.