ARG81400: Multi-Output Regulator with Buck or Buck/Boost Pre-Regulator, Synchronous Buck, 5x LDO Outputs, Watchdog, and SPI

The ARG81400 is rated up to 50V input and provides 6 total outputs. There are 5 LDOs, and a post regulated DC/DC switcher to power MCUs, as well as a watchdog, and SPI. Designed for high-temperature operation, the ARG81400 is ideal for Automotive and Industrial applications.

The device uses a buck or buck/boost pre-regulator to efficiently feed five linear regulators— 3.3 V / 90 mA, 5 V / 200 mA, 5 V / 30 mA, 5 V / 55 mA, and 5 V /100 mA (short-battery protected)—and an adjustable output, 600 mA synchronous buck.

Diagnostic outputs from the ARG81400 include a power-onreset output (NPOR), and a fault flag output to alert the microprocessor that a fault has occurred. The microprocessor can read fault status through SPI.

The ARG81400 contains a Window Watchdog timer with a programmable detect period. It enters an active state after NPOR transitions high and the processor has exercised the WD Test routine. The watchdog can be put into flash mode or be reset via secure SPI commands

Protection features include undervoltage and overvoltage on all output rails. In case of a shorted output, all linear regulators feature foldback overcurrent protection. In addition, the V5P output is protected from a short-to-battery event. Both switching regulators include pulse-by-pulse current limit, hiccup mode short-circuit protection, LX short-circuit protection, and thermal shutdown.

• A2-SIL™ compliant—device features for safety critical systems
• Automotive AEC-Q100 qualified
• Wide input voltage range, 3.8 to 40 VIN operating range, 50 VIN maximum
• Buck or buck/boost pre-regulator (VREG)
• Adjustable 1.25 to 3.3 V synchronous buck for powering a MCU
• Four internal linear regulators with foldback short-circuit protection, 3.3 V (3V3) and three 5 V (V5CAN, V5A, and V5B)
• One internal 5 V linear regulator (V5P) with foldback short-circuit and short-to-battery protection
• Pin-to-pin and pin-to-ground tolerant at every pin
• Power-on reset signal indicating a fault on the synchronous buck, 3V3 or V5A regulator outputs (NPOR)
• Window watchdog timer with fail-safe features
• Control and diagnostic reporting through a serial peripheral interface (SPI)
• Safety signal (POE) can disable a separate function (e.g., Motor Driver) due to a Watchdog Failure
• Frequency dithering and controlled slew rate helps reduce EMI/EMC
• OV and UV protection for all output rails