LTC3882_15 Datasheet, PDF (79/104 Pages) Linear Technology – Dual Output PolyPhase Step-Down DC/DC Voltage Mode Controller with Digital Power System Management

LTC3882
PMBus COMMAND DETAILS (Output Current and Limits)
OUTPUT CURRENT AND LIMITS
COMMAND NAME
CMD
CODE DESCRIPTION
DATA
DEFAULT
TYPE PAGED FORMAT UNITS NVM VALUE
IOUT_CAL_GAIN
0x38 Ratio of I_SENSE± voltage to sensed current. R/W Word Y
L11
mΩ l 0.63mΩ
0xB285
MFR_IOUT_CAL_GAIN_TC
0xF6 Output current sense element temperature R/W Word Y
coefficient.
CF ppm/°C l 3900ppm/°C
0x0F3C
IOUT_OC_FAULT_LIMIT
0x46 Output overcurrent fault limit.
R/W Word Y
L11
A
l 29.75A
0xDBB8
IOUT_OC_WARN_LIMIT
0x4A Output overcurrent warning limit.
R/W Word Y
L11
A
l
20.0A
0xDA80
Related commands: STATUS_IOUT, SMBALERT_MASK, READ_IOUT, MFR_IOUT_PEAK, READ_POUT, IOUT_OC_FAULT_RESPONSE, MFR_VOUT_AVP
IOUT_CAL_GAIN
The IOUT_CAL_GAIN command is used to set the resistance value of the output current sense element in milliohms.
This command has two data bytes in Linear_5s_11s format.
MFR_IOUT_CAL_GAIN_TC
The MFR_IOUT_CAL_GAIN_TC command sets the temperature coefficient of the output current sense element in
ppm/°C. Effective sense resistance, in milliohms, is computed by the LTC3882 as
R_SENSE = IOUT_CAL_GAIN • (1 + 1E-6 • MFR_IOUT_CAL_GAIN_TC • (READ_TEMPERATURE_1 – 27))
This command has two data bytes representing a 2’s compliment integer.
IOUT_OC_FAULT_LIMIT
The IOUT_OC_FAULT_LIMIT command sets the value of the instantaneous peak output current, in amperes, which
will cause the OC supervisor to detect an output overcurrent fault. The LTC3882 uses the computed effective sense
resistance and the voltage across the I_SENSE± inputs to determine the output current. The programmed limit voltage is
rounded to the nearest 0.4mV in a range from 0.0mV to 80.0mV. Output overcurrent faults are ignored during TON_RISE
and TOFF_FALL output sequencing.
This command has two data bytes in Linear_5s_11s format.
IOUT_OC_WARN_LIMIT
The IOUT_OC_WARN_LIMIT command sets the value of the output current measured by the ADC, in amperes, that causes
an output overcurrent warning. To provide meaningful responses, this value should be set below IOUT_OC_FAULT_LIMIT
minus 1/2 of the maximum anticipated ripple current. If the IOUT_OC_WARN_LIMIT is exceeded, the device:
• Sets the IOUT Bit in the STATUS_WORD
• Sets the I_OUT Overcurrent Warning Bit in the STATUS_IOUT Command
• Notifies the Host by Asserting ALERT, Unless Masked
Output overcurrent warnings are ignored during TON_RISE and TOFF_FALL output sequencing.
This command has two data bytes in Linear_5s_11s format.
For more information www.linear.com/LTC3882
3882f
79