TPS544B20

For whatever reason, that document does not seem to be available.  Let me see if I can track it down for you.

Hello- These devices are currently in "preview." The datasheet for these devices (TPS544C20, TPS544B20) will be available on the product folder when they're released to market. 

http://www.ti.com/product/tps544b20 

Hi

When do you plane to release this device?

Best regards,

Elad

Hi John,

   I have a question for TPS544B20.

   Do I need to program TPS544B20 thru PMBus each time I power it up? In another word, will the parameters I

programmed to TPS544B20 get lost each time I power it down?

Thanks,

Tony

Hi Tony - The TPS544B20 has built-in EEPROM non-volatile memory (NVM). You can program the device to your liking once, then issue the STORE_USER_ALL command to commit your configuration to NVM. After this, at subsequent power-ups, TPS544B20 will load the values you've stored. 

The datasheets are live on the product folder sites now (TPS544C20, TPS544B20). See the description of STORE_USER_ALL for a list of commands with EEPROM back-up

Hi Matt,

  Thanks for your answer. I have one more question.

  What is the story If I power up a brand new TPS544B20 without programming it? Is there a default configuration stored in NVM?

Thanks,

Tony

Hi Tony - Pg 27-29 of the datasheet show a table of its default EEPROM settings, and associated behavior. These can be changed and stored to EEPROM if desired, so that on subsequent power-on's the device will restore the settings you've chosen

http://www.ti.com/lit/gpn/tps544b20 

Hi all,

I'm attempting to programmatically control the tps544b20.  Could someone direct me to the documenation that:

1) speaks about how to do this

2) what commands to send to in order change the voltage?

Thanks!

Howard

Hi Howard - The TPS544B20 datasheet has a full command reference including all of the supported commands, and their data formats. The interface is PMBus, which is very similar to i2c. There's an explanatory app note about using i2c to implement PMBus, here:

http://www.ti.com/lit/an/sprabj6/sprabj6.pdf 

If you're just getting started, I would recommend using the Fusion GUI software + TI SAA adapter. More information is here: 

http://software-dl.ti.com/analog/analog_public_sw/fusion/TI-Fusion-Digital-Power-Designer-1.8.372.exe

http://www.ti.com/tool/fusion_usb_adapter_api

There is some good "getting started information in the EVM user's guide: http://www.ti.com/lit/pdf/sluuay7

2.) To adjus the output voltage, you can use two methods: (1) VREF_TRIM changes the default VREF from 0.6V from -20% to +10%. (2) Margin -- See the datasheet 

Matt,

Thank you for the references.  

I've tried programming tps44b20 through fusionparamwriter commandline.

I send the following command on the command prompt (windows )

FusionParamWriter --address 32  --cmd-id VREF_TRIM --value-encoded 0.01 --scan-mode combo

I've also tried the hex value for value-encoded.

and the error message i get is that the cmd-id is not recognized in both instances.

could you tell me the correct cmd-id to use to change VREF_TRIM?

or tell me what's wrong with the command that i'm sending above?

THanks,

Howard

Hello Howard - Its probably easiest to just use the CMD hex code. This should work:

FusionParamWriter.exe --address 32 --scan-mode device_code --cmd-id 0xD4 --value-encoded 0x0000

In general for Fusion "encoded" refers to hex value, "decoded" refers to human-readable value

matt, 

thanks!

I will try that.

is there documentation that describes the CMD hex code?  out of the ones i read, i couldn't find it.

Thanks!

howard

The table on pg.28-29 of the datasheet shows the command hex code for each supported register. These are defined by the PMBus spec. 

Matt,

i'm trying to send encoded hex values (instead of decoded decimal voltage values) to the tps540.

how does one covert from decimal\floating to the correct hex values?

alternatively where on the data sheet would the conversion algorithm be?

Thanks,

Howard

The description should be given in each command. A common data type for this device is "linear" format. Other commands use the VOUT_MODE command as an exponent

For a linear command, consider IOUT_OC_FAULT_LIMIT. The upper 5 bits are the exponent, and the lower 11 are the mantissa. 

IOUT_OC_FAULT_LIMIT = Mantissa * 2 ^(exponent)

The exponent is fixed at -1. In 2's complement binary this is 0b1111 1. 

The default value is 39A. If 39 = Mantissa * 2^(-1) --> Mantissa = 78 = 000 0100 1110

Putting the two together into one word we get 39A = 1111 1000 01000 1110 = 0xF84E. 

Other commands such as VREF_TRIM use the VOUT_MODE command as an exponent. For this device, VOUT_MODE is fixed at -9. For this type of command, all 16bits are the mantissa and VOUT_MODE is the exponent

For example to set VREF_TRIM = -0.06 V...

VREF_TRIM=Mantissa * 2^(exponent) = Mantissa * 2^(-9)

-0.06 = Mantissa * 2^(-9) --> Mantissa = -31 (rounding) = 0b1111 1111 1110 0001 = 0xFFE1