Datasheet

LTC3880/LTC3880-1
76
3880fc
For more information www.linear.com/LTC3880
PMBus COMMAND DETAILS
current limits are adjusted with temperature based on the MFR_IOUT_CAL_GAIN_TC using the equation:
IOUT_OC_FAULT_LIMIT = IOUT_CAL_GAIN • (1 + MFR_IOUT_CAL_GAIN_TC • (READ_TEMPERTURE_1-27.0)).
The LTpowerPlay GUI automatically convert the voltages to currents.
The I
OUT
range is set with bit 7 of the MFR_PWM_MODE_LTC3880 command.
The IOUT_OC_FAULT_LIMIT is ignored during TON_RISE and TOFF_FALL.
This command has two data bytes and is formatted in Linear_5s_11s format.
IOUT_OC_WARN_LIMIT
This command sets the value of the output current that causes an output overcurrent warning in amperes. The
READ_IOUT value will be used to determine if this limit has been exceeded.
In response to the IOUT_OC_WARN_LIMIT being exceeded, the device:
• Sets the NONE_OF_THE_ABOVE bit in the STATUS_BYTE
• Sets the IOUT bit in the STATUS_WORD
• Sets the IOUT Overcurrent Warning bit in the STATUS_IOUT command, and
• Notifies the host by asserting ALERT pin
This condition is detected by the ADC so the response time may be up to 100ms.
The IOUT_OC_FAULT_LIMIT is ignored during TON_RISE and TOFF_FALL.
This command has two data bytes and is formatted in Linear_5s_11s format
TEMPERATURE
External Temperature Calibration
COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS NVM
DEFAULT
VALUE
MFR_TEMP_1_GAIN 0xF8 Sets the slope of the external temperature
sensor.
R/W Word Y CF Y 1
0x4000
MFR_TEMP_1_OFFSET 0xF9 Sets the offset of the external temperature
sensor with respect to –273.1°C.
R/W Word
Y L11 C Y 0
0x8000
MFR_TEMP_1_GAIN
The MFR_TEMP_1_GAIN command will modify the slope of the external temperature sensor to account for non-idealities
in the element and errors associated with the remote sensing of the temperature in the inductor.
This command has two data bytes and is formatted in 16-bit 2’s complement integer. N = 8192 to 32767. The effective
adjustment is N • 2
–14
. The nominal value is 1.
MFR_TEMP_1_OFFSET
The MFR_TEMP_1_OFFSET command will modify the offset of the external temperature sensor to account for non-
idealities in the element and errors associated with the remote sensing of the temperature in the inductor.