Datasheet
LTC3880/LTC3880-1
75
3880fc
For more information www.linear.com/LTC3880
PMBus
COMMAND DETAILS
IIN_OC_WARN_LIMIT
The IIN_OC_WARN_LIMIT command sets the value of the input current, in amperes, that causes a warning indicating
the input current is high. The READ_IIN value will be used to determine if this limit has been exceeded.
In response to the IIN_OC_WARN_LIMIT being exceeded, the device:
• Sets the OTHER bit in the STATUS_BYTE
• Sets the INPUT bit in the upper byte of the STATUS_WORD
• Sets the IIN Overcurrent Warning bit in the STATUS_INPUT 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.
This command has two data bytes and is formatted in Linear_5s_11s format.
Output Current
COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED
DATA
FORMAT UNITS NVM
DEFAULT
VALUE
IOUT_OC_FAULT_LIMIT 0x46 Output overcurrent fault limit. R/W Word Y L11 A Y 29.75
0xDBB8
IOUT_OC_WARN_LIMIT 0x4A Output overcurrent warning limit. R/W Word Y L11 A Y 20.0
0xDA80
IOUT_OC_FAULT_LIMIT
The IOUT_OC_FAULT_LIMIT command sets the value of the peak output current limit, in amperes. When the controller
is in current limit, the overcurrent detector will indicate an overcurrent fault condition. The programmed overcurrent
fault limit value is rounded up to the nearest one of the following set of discrete values:
25mV/IOUT_CAL_GAIN Low Range (1.5x Nominal Loop Gain)
MFR_PWM_MODE_LTC3880 [7]=0
28.6mV/IOUT_CAL_GAIN
32.1mV/IOUT_CAL_GAIN
35.7mV/IOUT_CAL_GAIN
39.3mV/IOUT_CAL_GAIN
42.9mV/IOUT_CAL_GAIN
46.4mV/IOUT_CAL_GAIN
50mV/IOUT_CAL_GAIN
37.5mV/IOUT_CAL_GAIN High Range (Nominal Loop Gain)
MFR_PWM_MODE_LTC3880 [7]=1
42.9mV/IOUT_CAL_GAIN
48.2mV/IOUT_CAL_GAIN
53.6mV/IOUT_CAL_GAIN
58.9mV/IOUT_CAL_GAIN
64.3mV/IOUT_CAL_GAIN
69.6mV/IOUT_CAL_GAIN
75mV/IOUT_CAL_GAIN
Note: This is the peak of the current waveform. The READ_IOUT command returns the average current. The peak output