The TPS65381-Q1 device is a multi-rail power supply designed to supply microcontrollers (MCUs) in functional safety applications, such as those found in automotive and industrial applications. The device supports Texas Instruments’ TMS570LS series flash MCU and other MCUs with dual-core lockstep (LS) or loosely-coupled architectures (LC).
The TPS65381-Q1 device integrates multiple supply rails to power the MCU, CAN, or FlexRay, and an external sensor. An asynchronous-buck switch-mode power-supply converter with an internal FET converts the input battery voltage to a 6-V preregulator output. This 6-V preregulator supplies the other regulators. Furthermore, the device supports wake-up from IGNITION or wake-up from the CAN transceiver.
A fixed 5-V linear regulator with an internal FET is integrated to be used as a CAN supply (as one example). A second linear regulator, also with an internal FET, regulates the 6 V to a selectable 5-V or 3.3-V MCU I/O voltage.
The TPS65381-Q1 device comprises a linear regulator controller with an external FET and resistor divider that regulates the 6 V to an externally adjustable core voltage of between 0.8 V and 3.3 V.
The device comprises a sensor supply with short-to-ground and short-to-battery protection. Therefore this supply can power a sensor outside the electronic-control unit (ECU).
The device has an integrated charge pump to provide overdrive voltage for the internal regulators. Reverse-battery protection is obtained by using the charge-pump output to control an external NMOS transistor. This solution allows for a lower minimum-battery-voltage operation compared to a traditional reverse-battery blocking diode.
The device monitors undervoltage and overvoltage on all regulator outputs, battery voltage, and internal supply rails. A second bandgap reference, independent from the main bandgap reference, is used for the undervoltage and overvoltage monitoring, to avoid any drifts in the main bandgap reference from being undetected. In addition, regulator current-limits and temperature protections are implemented.
The TPS65381-Q1 has monitoring and protection functions which include the functions as follows: watchdog with trigger and modes, MCU error-signal monitor, clock monitoring on internal oscillators, self-check on the clock monitor, CRC on non-volatile memory, a diagnostic output pin allowing the MCU to observe the internal analog and digital signals of the device, a reset circuit for the MCU, and an enable drive output to disable the safing-path or external power-stages on detected faults. A built-in self-test (BIST) monitors the device functionality at start-up. A dedicated DIAGNOSTIC state allows the MCU to check TPS65381-Q1 monitoring and protection functions.
The TPS65381-Q1 device is offered in a 32-pin HTSSOP PowerPAD package.
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