• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 73 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS546D24S: Replacing TPS546A24A to TPS546D24S Changes on the Firmware using I2C/PMBUS

sal hash
Prodigy 65 points
Part Number: TPS546D24S
Other Parts Discussed in Thread: TPS546A24A

Tool/software:

I am upgrading my system by replacing TPS546A24A to TPS546D24S as they are pin compatible; should i need to make any changes on the firmware programming in order to communicate (i2c or PMbus) or not?

If yes then what are things should i change?

I just want to read the Voltage, Current and temperature of the TPS546D24S  and change the output voltage using PMBUS.

Thanks in advance

  • +1
    TI__Genius 11276 points

    Hi Sal,

    Keep in mind the TPS546A24A (10A) and TPS546D24S (40A) are pin to pin, but not drop in compatible. Therefore, you will likely need to make some changes to the loop compensation (COMPENSATION_CONFIG), either through pinstrap or PMBus, and LC selection. Telemetry for VOUT, IOUT, etc., will be the same. More details below:

    1) The current sense gain for the TPS546A24A is higher (12.31mV/A) than the TPS546D24S (6.155mV/A).  For the same inductor value, the TPS546A24A will only be able to support 1/2 the current loop gain that the TPS546D24S supports.  For the same Output capacitors, the TPS546A24A will be able to support 2x the voltage loop gain, but will need 2x the voltage loop gain to achieve the same bandwidth and transient performance.

    2) The MSEL2 current limit programing options for the TPS546A24A are different than the TPS546D24S.  They are generally about 1/4 the current limit for the TPS546D24S using the same resistor options

    3) The programmable range of the current limit functions on the TPS546A24A are much lower than those allowed on the TPS546D24S.

    4) Make sure your system firmware is tolerant of the different IC_DEVICE_ID and IC_DEVICE_REV. 

    Thank you,
    Tomoya