The TPS65381A-Q1 device is a multirail power supply designed to supply microcontrollers (MCUs) in safety-relevant applications, such as those found in automotive and industrial markets. The device supports Texas Instruments’ Hercules™ TMS570 MCU and C2000™ MCU families, and various other MCUs with dual-core lockstep (LS) or loosely-coupled architectures (LC).
The TPS65381A-Q1 device integrates multiple supply rails to power the MCU, controller area network (CAN), or FlexRay, and an external sensor. An asynchronous-buck switch-mode power-supply converter with an internal FET converts the input supply (battery) voltage to a 6-V preregulator output. This 6-V preregulator supplies the other regulators. The device supports wakeup from IGNITION or wakeup from the CAN transceiver.
The integrated, fixed 5-V linear regulator with internal FET can be used for a CAN or FlexRay transceiver supply for example. A second linear regulator, also with an internal FET, regulates to a selectable 5-V or 3.3-V output which, for example, can be use for the MCU I/O voltage.
The TPS65381A-Q1 device includes an adjustable linear-regulator controller, requiring an external FET and resistor divider, that regulates to an adjustable voltage of between 0.8 V and 3.3 V which may be used for the MCU core supply.
The integrated sensor supply can be run in tracking mode or adjustable output mode and includes short-to-ground and short-to-battery protection. Therefore, this regulator can power a sensor outside the module or electronic control unit (ECU).
The integrated charge pump provides overdrive voltage for the internal regulators. The charge pump can also be used in a reverse-battery protection circuit 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 when the device must be operational at the lowest possible supply voltages.
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 TPS65381A-Q1 device has monitoring and protection functions, which include the following: watchdog with trigger and question and answer modes, MCU error-signal monitor, clock monitoring on internal oscillators, self-check on the clock monitor, cyclic redundancy check (CRC) on nonvolatile memory, a diagnostic output pin allowing the MCU to observe internal analog and digital signals of the device, a reset circuit and output pin 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 automatically at power-up. A dedicated DIAGNOSTIC state allows the MCU to check TPS65381A-Q1 monitoring and protection functions.
The TPS65381A-Q1 device is offered in a 32-pin HTSSOP PowerPAD package.