TPS65987D: Design PDO question for TPS65987D

Jianping

Part Number: TPS65987D
Other Parts Discussed in Thread: LM5176

Hi.

i have some quetion by this part(TPS65987D).

1、If we base on TT Mode by design PDO(becuase referece Design for 4pcs PDO-5,9,15,20V;we need 5pcs PDO-5 9 12 15 20V) ,is it add decorder(3:8) ?

or as below design?or other referece design at TI side? or like the TBT3 design TT mode(MP2491C include decorder)?

2、are these have the PDO voltage sequence(ext,default:5 9 12 15 20),are they change to 5 9 15 20 12V ，is it support ?

3、are they running TT Mode(true table mode),all PDO pins at low if no PDO mode?

4、How many PDOs for deafult on the TPS65987D ? and which GPIO pins setting it better? are they reference the EVM design is OK?

thanks!

over 6 years ago

0 Eric Beljaars over 6 years ago

TI__Mastermind 36756 points

Hello,

1. Yes, the TPS65987D can support the 5 PDOs that you listed. The Truth Table GPIO events can be used for this.
2. The sequence should follow how you want the Truth Table GPIOs to be triggered.
3. If no PDO is selected, all the truth table GPIOs will be low.
4. The TPS65987D Can support up to 7 PDOs. To support the 5 that you listed, I would suggest using the Truth Table Source GPIO events.

Thank you,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

thanks!

as you said ,the support 5 PDOs must by the TT Mode(true table),is right?

and could you tell me ,how to design the schematic?is it contact to FB pin(controll the N-Mos) direct?or by decorder(3:8),one by one controll the N-Mos for FB pin voltage?

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

about the TT Mode,how to contact to the feedback for the PD regulator?is it contact direct or via the 3:8 decorder?

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

The design of the feedback for the PD regulator is up to the user for their design. The PD controller will output the GPIOs in a truth table manner based on the selected PDO.

Thanks,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

Yes,our design the PDO regulator by LM5176 .

but be calulation the resistor of FB pin(as below part ) very difficult .

speical the 15V PDO.can't calulation the normal value .

they are easy calulation if used the 3:8 decorder.

one by one controller the resistor for the FB voltage (PDO voltage).

so ,i don't know how to design,need you more help.

thanks!

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

I would suggest asking a new question with LM5176 as the part number to receive support from that devices expert.

Thank you,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

OK, i'll check it with LM5176 AE together.

an other:

1、 we are configuration the event of GPIO ,about the sequence ,which event is slowly for the" port0 Plug event and Port0 Cable Orientation event"

because we need the" Port0 cable orientation event" inform the HUB CC Pin, then enable the Plug.

2、 aboout the I2C2_SCL and I2C_SDA, is it update FW by Pin header contact directly or contact to TBT only.

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

1. Plug Event and Cable Orientation Event can be used at the same time on different GPIOs if needed.
2. I2C2 should be connected to the TBT controller.

Thank you,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

1、Cable Orientation Event be assert first,then assert Plug Event ,can them configruation by tools?

2、yes,design guide for I2C2 should be TBT contact.but i checked the EVM board,it is contact to I2C of FTDI（FT4232HL).

if we 'll use this port updated FW by pin header contact,is it OK?

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

1. No, the timing of when GPIOs are triggered cannot be configured. If this is needed, I would suggest handling it in another part of the system, the TPS65987D does not have this flexibility with the GPIOs.
2. The EVM does not have a TBT controller so I2C2 on the EVM is used for the FTDI. If you don't have a TBT controller on your system, I2C2 can be connected to another I2C master.

Thanks,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric;

about item1.we are need a GPIO of TPS65987D for GL3590 enable .

but the Genesisy said ,must be orientation first,then enable(Highlevel) the HUB.

so i am configruation the function of GPIO.

which one sequence first if configruation for"VBUS Detect Event" and orientation event"?

could you help to me confirm other event delya the "orientation event"if the Vbus detect event" didn't matching.

thanks!

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

We do not specify timing for these GPIOs. If you need to meet a certain timing requirement, I would suggest using the embedded controller in the system instead of the PD controller.
If you have a TPS65987EVM, you can measure the GPIO timings to see if they meet your requirements.

Thanks,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

1、like you said,i checked these timming on the EVM,they are timming same as(USB3 event and orientation event).

so ,i'll add a "BU4210GTR"(see attached file) part on the USB3 event GPIO for delay it.

2、about the I2C1 and I2C2, are they both updated FW function?

the I2C1 connect online Master,the other I2C2 connect the Pin header master.

and one by one application,don't use by same time.

are these connect is OK?

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

I2C1 can be either a master or a slave on the TPS65987D, it is configurable through the TPS6598x Application Customization Tool. I2C2 is a slave only port on the TPS65987D.

Thank you,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

about upon questions,could you help me confirm the item1?

is it have any latency?

thanks!

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

We do not specify exact timing for the GPIOs. I would suggest controlling the signals through another chip if precise timing is a requirement.

Thanks,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

HI,Eric:

OK,i'll add a delay time IC for it.

another;

what did damage for configuration the GPIO event "assert Low if no PDO(as below) "?

becuase we'll controll other Power output if no PDO mode.

pls help to review it.

thanks!

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

Yes, the Source PDO GPIOs will be low when the corresponding PDO has not been negotiated.

Thanks,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

our project need 5 PDOs(5 9 12 15 15 20V), as with you check on first, it's configruation at TT Mode for more PDOs.

but i checked the GPIO event guide(as below diagram),they GPIOs for "input",is it external true table contact to our TPS65987D

or like our design,the 3 PDOs contact to FB directly?

an other :

about the I2C address selection one from the datasheet and the other from user guide,

could you explain them function？and how to use them?

thanks!

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

The Feedback network for your DC/DC looks correct to me if the math is correct. The connections look correct to me.
As far as the I2C2 address is concerned. You need to place a resistor divider from LDO_3V3 to Gnd on the ADCIN2 pin. Figure 32 in the datasheet highlights how this can be done.

Thank you,
Eric

0 Jianping over 6 years ago in reply to Eric Beljaars

Intellectual 550 points

Hi,Eric:

we are know, the TPS65987D have 4pcs PDO by GPIO mode at normal setting,

could they set 4PCS PDO by GPIO mode ,the other PDO by TT(MSB)Mode if 5PCS PDO mode .

0 Eric Beljaars over 6 years ago in reply to Jianping

TI__Mastermind 36756 points

Hello,

Yes, if you set 3 GPIOs to TT mode for source PDOs, then up to 7 PDOs can be supported.

Thanks,
Eric

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TPS65987D: Design PDO question for TPS65987D