Datasheet

LTC3880/LTC3880-1
74
3880fc
For more information www.linear.com/LTC3880
PMBus COMMAND DETAILS
CURRENT
Input Current Calibration
COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS NVM
DEFAULT
VALUE
MFR_IIN_OFFSET 0xE9 Coefficient used to add to the input current to
account for the IQ of the part.
R/W
Word
Y L11 A Y 0.050
0x9333
MFR_IIN_OFFSET
The MFR_IIN_OFFSET command allows the user to set an input current representing the quiescent current of each
channel. For accurate results at low output current, the part should be in continuous conduction mode.
This command has 2 data bytes and is formatted in Linear_5s_11s format.
Output Current Calibration
COMMAND NAME
CMD
CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS NVM
DEFAULT
VALUE
IOUT_CAL_GAIN 0x38 The ratio of the voltage at the current sense pins
to the sensed current. For devices using a fixed
current sense resistor, it is the resistance value
in mΩ.
R/W Word Y L11 mΩ Y 1.8
0xBB9A
MFR_IOUT_CAL_GAIN_TC 0xF6 Temperature coefficient of the current sensing
element.
R/W Word Y CF Y 3900
0x0F3C
IOUT_CAL_GAIN
The IOUT_CAL_GAIN command is used to set the resistance value of the current sense resistor in milliohms. (see
also MFR_IOUT_CAL_GAIN_TC).
This command has two data bytes and is formatted in Linear_5s_11s format.
MFR_IOUT_CAL_GAIN_TC
The MFR_IOUT_CAL_GAIN_TC command allows the user to program the temperature coefficient of the IOUT_CAL_GAIN
sense resistor or inductor DCR in ppm/°C.
This command has two data bytes and is formatted in 16-bit 2’s complement integer ppm. N = –32768 to 32767 •
10
–6
. Nominal temperature is 27°C. The IOUT_CAL_GAIN is multiplied by:
[1.0 + MFR_IOUT_CAL_GAIN_TC • (READ_TEMPERATURE_1-27)]. DCR sensing will have a typical value of 3900.
The IOUT_CAL_GAIN and MFR_IOUT_CAL_GAIN_TC impact all current parameters including: READ_IOUT, READ_IIN,
IOUT_OC_FAULT_LIMIT and IOUT_OC_WARN_LIMIT.
Input Current
COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS NVM
DEFAULT
VALUE
IIN_OC_WARN_LIMIT 0x5D Input overcurrent warning limit. R/W Word N L11 A Y 10.0
0xD280