LTC2972 without control the voltage of DCDC

Hi Kokubo-san,

Yes, the 2972 DAC pin may be left floating.  They should also consider the following configuration settings.

On channels that are monitor/supervise only and use VOUT_EN to enable the channel:
- Configure OPERATION register to ‘On’ (0x80)
- Configure ON_OFF_CONFIG to a value of 0x1E (respond to both PMBus and CONTROL pin)
- Configure the DAC mode to ‘disconnected’ (in MFR_CONFIG)

The Vout OV and UV supervisors are still operational, so they should set the OV/UV limits that are appropriate for the nominal Vout voltage.

Mike

Hi Mike-san,

Thank you for your advice.

Should we only write 0b01 to MFR_CONFIG_LTC2972[5:4] for DAC mode ‘disconnected ’?

Best regards

N.Kokubo

Hi Mike-san,

Thank you for your advice.

Should we only write 0b01 to MFR_CONFIG_LTC2972[5:4] for DAC mode ‘disconnected ’?

Best regards

N.Kokubo

Yes, that is correct.  To be clear, you must write 2 bytes.  The default value for MFR_CONFIG is 0x0080, and if DAC is disconnected, the value is 0x0090.

Mike

Hi Mike san

Thank you for promt reply.

I close this question.

Best regards

N.Kokubo