TPS65381A-Q1 Datasheet, PDF (2/7 Pages) Texas Instruments – Multi-Rail Power Supply for Microcontrollers in Safety Applications

TPS65381A-Q1
SLVSDJ1 – JULY 2016
www.ti.com
1.2 Applications
• Safety Automotive Applications
– Power Steering: Electrical Power Steering
(EPS) and Electro Hydraulic Power Steering
(EHPS)
– Braking: Anti-Lock Brake System (ABS),
Electronic Stability Control (ESC), and Electric
Parking Brake
– Advanced Driver Assistance Systems (ADAS)
– Suspension
• Industrial Safety Applications
– Safety Programmable Logic Controllers (PLCs)
– Safety I/O Control Modules
– Test and Measurement
– Railway and Subway Signal Control and
Safety Modules
– Elevator and Escalator Safety Control
– Wind Turbine Control
1.3 Description
The TPS65381A-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 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 battery voltage to a 6-V preregulator output. This 6-V preregulator
supplies the other regulators. 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 TPS65381A-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 TPS65381A-Q1 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 non-volatile memory, a diagnostic
output pin allowing the MCU to observe 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 TPS65381A-Q1 monitoring and protection functions.
The TPS65381A-Q1 device is offered in a 32-pin HTSSOP PowerPAD package.
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