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).
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
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.
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 TPS65381-Q1 monitoring and protection functions.
device is offered in a 32-pin HTSSOP PowerPAD package.