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Original question:

BQ24610: BQ24610EVM

TPS65987D: TPS65987D Design Questions

mbbrouwer
Expert 3200 points
Part Number: TPS65987D
Other Parts Discussed in Thread: TVS2200,

HI there, I have a customer that has some questions. Schematic related questions I will send internally.

1) what package resistor should they use for the components Cap and 3.48 ohm shown for the snubber circuit (Figure 35 in datasheet),   0402 / 0603 / 0805 / 1206 ?

1b) customer is also using a TVS2200 for protection right at the USB-C connector, is this sufficient to prevent protection for any voltage spikes above 20V? I noticed in an e2e post we recommend this part. Have we done any test data for this? Any preference to snubber vs TVS or having both populated?

2) On 3V3_LDO the output is 25mA max, even when fed from an external switcher on 3V3IN that can provide more than 25mA ?

3) PP_CABLE – since we they are not using it,  then pin must be grounded or best to have pull up and pull down option for future need?

4)      BOOT - ADCIN1 if our equipment is going be the sink device, using a power adaptor of 15V @ 3A max & we will also use it as OTG 5V up to 1A, what is the best option to program for ADCIN1 among the many choices ?

  1. Dead battery – BP_Wait for 3V#_Internal ?
  2. Configuration 3 ?

5)      Does an errata exist for this device ? The latest firmware revisions are in the TI config tool. Do we have any H/W errata? I believe no but need to ask….

6)  There is no indication that the signal MISO (pin 5 on the SPI Flash) needs a pull. Does it need a pull-up ?

6b) There is no indication that the signal CLK (pin 6 on the SPI Flash) needs a pull. Does it need a pull-up ?

Many thanks for your help Guys!

              

  • 0
    TI__Genius 12700 points

    Hello,

    For the Snubber circuit, the customer could use the same one that the EVM User's Guide shows in the Layout and Bill of Materials section, which seems to be the 3.48 Ohm resistor and a 4.7uF capacitor but the package type for them will depend on the power dissipation of the circuit. For the TVS2200, if this part was recommended for specifically the protection for this TPS65987D PD controller, I would also recommend going with that. I can check with the team this week to see if there is another recommendation.

    I'm not sure I understand your 2nd questions. Are you saying that you need the LDO_3V3 to output high current? The absolute maximum Iload for that signal is up to 50mA as it's only used for the internal circuitry. 

    You will need to have power on the PP_Cable signal since this signal powers the CC line. I would recommend looking at the Power Supply Requirements and Characteristics section in the datasheet for the requirements of this signal.

    For the boot mode, it will depend on if your customer will have a Flash or not. If they do, they can have the device be in one of the dead battery modes while waiting for the patch to come through via Flash, or use one of the default configurations, such as configuration 3 and BP_NoWait dead battery configuration if they won't be using Flash or a Host to program their own configurations.

    At the moment, no unfortunately, there isn't an errata for this part.

    For the SPI signals, MISO and CLK, no you don't need a pull-up as it will connect directly to the Flash if the customer is using one. 

    For additional information or details on certain parts, I would also recommend showing the customer to our Application Notes on this PD controller located in the "Technical Documentation" Tab of the product page as it covers in-depth information on a specific application for our PD devices.

    Thank you,

    Hari