LTC3883 Datasheet, PDF (79/112 Pages) Linear Technology – Single Phase Step-Down DC/DC Controller with Digital Power System Management

LTC3883/LTC3883-1
PMBus Command Details
External Temperature Limits
COMMAND NAME
OT_FAULT_LIMIT
CMD CODE DESCRIPTION
0x4F External overtemperature fault limit.
OT_WARN_LIMIT
0x51 External overtemperature warning limit.
UT_FAULT_LIMIT
0x53 External undertemperature fault limit.
TYPE
R/W Word
DATA
FORMAT
L11
UNITS
C
R/W Word L11
C
R/W Word L11
C
DEFAULT
NVM
VALUE
Y
100.0
0xEB20
Y
85.0
0xEAA8
Y
–40.0
0xE580
OT_FAULT_LIMIT
The OT_FAULT_LIMIT command sets the value of the external sense temperature, in degrees Celsius, which causes an
overtemperature fault. The READ_TEMPERATURE_1 value will be used to determine if this limit has been exceeded.
This condition is detected by the ADC so the response time may be up to 120ms.
This command has two data bytes and is formatted in Linear_5s_11s format.
OT_WARN_LIMIT
The OT_WARN_LIMIT command sets the value of the external sense temperature, in degrees Celsius, which causes an
overtemperature warning. The READ_TEMPERATURE_1 value will be used to determine if this limit has been exceeded.
In response to the OT_WARN_LIMIT being exceeded, the device:
• Sets the TEMPERATURE bit in the STATUS_BYTE
• Sets the Overtemperature Warning bit in the STATUS_TEMPERATURE command, and
• Notifies the host by asserting ALERT pin.
This condition is detected by the ADC so the response time may be up to 120ms.
This command has two data bytes and is formatted in Linear_5s_11s format.
UT_FAULT_LIMIT
The UT_FAULT_LIMIT command sets the value of the external sense temperature, in degrees Celsius, which causes
an undertemperature fault. The READ_TEMPERATURE_1 value will be used to determine if this limit has been
exceeded.
Note: If the temp sensors are not installed, the UT_FAULT_LIMIT can be set to –275°C and UT_FAULT_LIMIT response
set to ignore to avoid ALERT being asserted.
This condition is detected by the ADC so the response time may be up to 120ms.
This command has two data bytes and is formatted in Linear_5s_11s format.
3883f
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