LTC7151S datasheet(18/38 Pages) AD

18 / 38 page

LT7182S

Rev. 0

For more information www.analog.com

OPERATION

• Shut down immediately and latch off

The remainder of this section describes the factory default

warning and fault behavior. See Table 1.

See the LT7182S PMBus/I2C Reference Manual for details

on configuring fault and warning behavior.

All faults and warnings are indicated in PMBus STATUS

commands.

When a warning occurs related to output voltage, output

current, or temperature, the LT7182S pulls the ALERT

pin low, the corresponding bit is set in the appropriate

STATUS command(s), and the channel continues to

operate.

If the output voltage falls below VOUT_UV_FAULT_LIMIT,

the LT7182S responds as follows:

• The channel’s PGOOD pin is pulled low

• The ALERT pin is pulled low

• The VOUT_UV fault bit is set in the STATUS_VOUT,

STATUS_BYTE, and STATUS_WORD commands.

• The channel continues to operate while limiting the

maximum valley current

If a fault occurs due to output overvoltage, or input over-

voltage, the LT7182S responds as follows:

• The faulted channel(s) are shut down immediately.

• The channel’s FAULT pin and PGOOD pin are pulled low

• The ALERT pin is pulled low

• The corresponding indicator bit(s) are set in the appro-

priate STATUS command(s)

• After 10ms (time defined by MFR_RETRY_DELAY), the

channel attempts to restart when the fault condition is

no longer present

If a fault occurs due to overtemperature, the LT7182S

responds as follows:

• Both channels are shut down immediately.

• Both channels’ FAULT pins and PGOOD pins are

pulled low

• The ALERT pin is pulled low

• The overtemperature (OT) bit is set in the appropriate

STATUS command(s)

• When the ADC measures that the temperature is below

the overtemperature threshold, the channel attempts

to restart

The LT7182S periodically compares the primary internal

voltage reference against a secondary internal voltage ref-

erence using the ADC. If a failure is detected, the LT7182S

responds as follows:

• Both channels are shut down immediately.

• The FAULT pins, PGOOD pins, and ALERT pins are

pulled low

• The internal reference fault bit is set in the STATUS

commands

• Both channels remain off unless the reference recovers

(for example due to temperature drift), a RESTORE_

USER_ALL or MFR_RESET command is received, or

input power is removed from both PVIN0 and EXTVCC

FAULT Pins

A fault will cause the FAULT pin to pull low if the corre-

sponding FAULT_RESPONSE command is programmed

to shut down the regulator output and the MFR_FAULT_

PROPAGATE_LT7182S command is configured to prop-

agate the fault to the open-drain FAULT pins.

Once the LT7182S pulls down a FAULT pin, the device

will continue to hold the pin low until one of the following

occurs:

• The channel retries, for faults that are configured to

retry

• The faulted channel is disabled then re-enabled

• A RESTORE_USER_ALL or MFR_RESET command is

received

• Input power is removed from both PVIN0 and EXTVCC

The FAULT pin can also be used as an input to provide a

method for the LT7182S to respond to external faults. The

channel turns off immediately if the channel’s FAULT pin is

pulled low externally. This enables coordination of faults

among multiple power system management products.

LTC7151S Datasheet(PDF) 18 Page - Analog Devices

LTC7151S Datasheet(HTML) 18 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

Datasheet Download

Link URL