Datasheet

LTC3880/LTC3880-1

3880fc

For more information www.linear.com/LTC3880

PMBus

COMMAND DETAILS

This command has two data bytes and is formatted in Linear_5s_11s format. The part starts the calculation with a

value of –273.15 so the default adjustment value is zero.

External Temperature Limits

COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED

DATA

FORMAT UNITS NVM

DEFAULT

VALUE

OT_FAULT_LIMIT 0x4F External overtemperature fault limit. R/W Word Y L11 C Y 100.0

0xEB20

OT_WARN_LIMIT 0x51 External overtemperature warning limit. R/W Word Y L11 C Y 85.0

0xEAA8

UT_FAULT_LIMIT 0x53 External undertemperature fault limit. R/W Word Y L11 C 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 100ms.

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 100ms.

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_F

AUL

T_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 100ms.

Values of greater than 0.1V/ms and less than or equal to 1V/ms are recommended. If a transition rate out of this range

is desired, contact the factory for more information.

This command has two data bytes and is formatted in Linear_5s_11s format.