Some document for connection between TPS65381-Q1 and TMS570.

Hi Nakai-san,

 

The exact connections will be specific to the application and use case of the customer but there are a several examples to use as starting points.

 

For the TPS65381 application circuits use the datasheet application sections and the EVM for the TPS6531 as a starting point: http://www.ti.com/product/TPS65381-Q1

The TPS65381 Safety Manual also shows high level connections between the TPS65381-Q1 and a TMS570. The EVM User's Guide and Safety Manual are in the Technical Documents folder:  http://www.ti.com/product/TPS65381-Q1/technicaldocuments

 

There is a control card where the TPS65381-Q1 is on the same PCB with a Hercules TMS570LS12x/11x. This may be used as an example in more detail.  It may not be the specific TMS570 being used, but should be a very good starting point. http://www.ti.com/tool/tmdx570ls12cncd    there is a link on this product page called "MotorWare Software Projects for Hercules Safety MCU's v1.03.03.03".  If you download and install this Motorware library, it will put a files on your PC that include schematics for the control card where the TPS65381 is connected to the TMS570.  This file is in the path:  C:\ti\Hercules\MotorWare\v1.0.3.03\sw\boards\control\tmdx570ls12cncd     The schematics are tms570ls12CNCD_iso_cpld.pdf, the other files are the user guide and layout. 

 

The key connections will be:

1. Power - The TPS65381-Q1 can supply:

   1. the core with 1.2V up to 600mA using the VDD1 LDO controller

   2. the IO at 3.3V using VDD3/5 in 3.3V mode.

2. SPI - the main control of the TPS65381-Q1 will be via the SPI so it needs to be connected (SCLK, SDI, SDO, NCS)

3. IO monitoring and RESET:

   1. nRES may be used to control reset of the MCU (PORRST) or other peripherals in the system

   2. ENDRV pin is the "safing" enable output of the TPS65381 and may need to be monitored by the MCU.

   3. WDI/ERROR pin is used for the MCU Error Signal Monitor for MCU lockstep monitoring (with the TPS65381 MCU ESM in TMS570 mode - nERROR)

   4. DIAG_OUT pin may be connected to an ADC channel to monitor the analog mux output and the digital outputs or it may be connected to both and ADC and a digital input if the digital mux outputs concept is to use a digital input (ADC and / or digital input)

4. Waking the TPS65381 up: IGN or CANWU will be needed to wake or start up the device. See the TPS65381 datasheet for both automotive and industrial examples and info.

Best Regards,

Scott

Hello Scott,

Thank you very much for your prompt reply.

I received a question from the customer.

Could you please answer the following questions?

> Is there any example circuit that the correct voltage is supplied to the input voltage of Hercules(TMS57 or RM46) ADC reference input (ADREFHI/ADREFLO) to check whether ADC is working correctly or not?

And the following is a few questions from me.

> I downloaded the schematic from Three-Phase BLDC / PMSM Motor Drive with High-Performance Microcontrollers Reference Design (TIDM-RM46XDRV8301KIT: e2e.ti.com/.../516016). In the schematic, I found TPS65381 DIAG_OUT is connected to AD1IN0 of RM46. What purpose is the connection. Is it for checking whether TPS65381 is working correctly or Hercules (RM46) ADC is working correctly?

> I'm sorry to ask you a basic question. Why TPS65381 is reccomended to use for safety application?

Could you please reply and teach me ?

Thank you and best regards,
Kazuya Nakai.

Hello Scott,

Could you please reply for my questions?

We need your help.

Thank you and best regards,
Kazuya Nakai.

Hello Nakai-san,

Q1 > Is there any example circuit that the correct voltage is supplied to the input voltage of Hercules(TMS57 or RM46) ADC reference input (ADREFHI/ADREFLO) to check whether ADC is working correctly or not?

A1>  I'm not aware of one, but you could ask on the Microcontroller forum, the checking of the ADC function on the MCU would need to be addressed by their product experts.   

Q2 > I downloaded the schematic from Three-Phase BLDC / PMSM Motor Drive with High-Performance Microcontrollers Reference Design (TIDM-RM46XDRV8301KIT: e2e.ti.com/.../516016). In the schematic, I found TPS65381 DIAG_OUT is connected to AD1IN0 of RM46. What purpose is the connection. Is it for checking whether TPS65381 is working correctly or Hercules (RM46) ADC is working correctly?

A2>  DIAG_OUT pin is a multiplexed output pin where both TPS65381-Q1 internal analog signals (such as voltage references, supply voltates, etc) and digital signals (monitoring, comparator output, clocks, etc) may be brought out to the MCU on either ADC or digital I/O.  In this way the MCU can perform independent monitoring for example of the TPS65381 clock to make sure it is correct, or that a voltage reference is correct.  By utilizing this well the MCU and software flow can add diagnostic coverage to the system to potential help meet system level safety goals.   

Q3 > I'm sorry to ask you a basic question. Why TPS65381 is reccomended to use for safety application?

A3>  This device provides many diagnostic and protection features such as the DIAG_OUT, independent regulation and monitoring circuits, watchdog, MCU ESM, safing output, etc to help the system designer meet their safety goals.  When these features can be used appropriately in their application it will help them with functional safety system design.  We also provide the Safety Manual on www.ti.com and the FMEDA (FIT rates, FMEDA, Pin FMEA) information under NDA to help the customer assess and document the use of this device in their functional safety system. These features and documentation are not available on normal catalog PMICs or discrete power supply devices. 

Best Regards, Scott

Hello Scott,

Thank you very much for your answer.
I could understand well because of the answers.

Thank you again and best regards,
Kazuya Nakai.