LT8708-1
22
Rev 0
For more information
and limiting circuitry, it can be configured with redundant
current limiting. It is recommended to set the slave input
current limit magnitudes to be the same or higher than
those set by the master. See the Applications Information
section for more information about the I
IN(SLAVE)
current
monitoring and limiting.
As with the LT8708, the LT8708-1 requires a 17.4k
resistor and parallel filter capacitor to be connected from
ground to the IMON_INP pin when using the RHCM con-
duction mode. If, in this case, it is also desired to set the
LT8708-1’s positive I
IN(SLAVE)
current limit higher than
the LT8708’s positive I
IN(MASTER)
limit, reduce the value
of the LT8708-1’s R
SENSE1
resistor as compared to the
LT8708’s R
SENSE1
value. See Configuring the I
Current Limits section for details.
MULTIPHASE CLOCKING
A multiphase application usually has switching regulators
operating at the same frequency but at different phases to
reduce voltage and current ripple. The SYNC pin can be
used to synchronize the LT8708-1’s switching frequency
at a specific phase relative to the master LT8708 chip. A
separate clock chip, e.g., LTC6902, LTC6909 etc., can be
used to generate the clock signals and drive the SYNC
pins of the LT8708 and LT8708-1(s). If only two phases
are needed for the multiphase application, i.e., 0° and
180°, the LT8708-1’s SYNC pin can be connected to the
LT8708’s CLKOUT pin to obtain the 180° phase shift. The
master LT8708 can be synchronized to an external source
or can be free-running based on the external R
T
resistor.
It is recommended that the LT8708-1 is always synchro-
nized to the same frequency as the LT8708 through the
SYNC pin.
OPERATION
