LT8708
14
Rev 0
For more information
RVSOFF
(Pin 25): Reverse Conduction Disable Pin. This
is an input/output open-drain pin that requires a pull up
resistor. Pulling this pin low disables reverse current op-
eration. See the Uni and Bidirectional Conduction section
for more information.
VOUTLOMON (Pin 26): V
OUT
Low Voltage Monitor Pin.
Connect a ±1% resistor divider between V
OUT
, VOUT-
LOMON and GND to set an undervoltage level on V
OUT
.
When V
OUT
is lower than this level, reverse conduction is
disabled to prevent drawing current from V
OUT
. See the
Applications Information section for more information.
VINHIMON (Pin 27): V
IN
High Voltage Monitor Pin. Con-
nect a ±1% resistor divider between V
IN
, VINHIMON and
GND in order to set an overvoltage level on V
IN
. When V
IN
is higher than this level, reverse conduction is disabled
to prevent current flow into V
IN
. See the Applications
Information section for more information.
ICP (Pin 28): Positive V
OUT
Current Monitor Pin. The cur-
rent out of this pin is 20μA plus a current proportional to
the positive average V
OUT
current. See the Applications
Information section for more information.
EXTV
CC
(Pin 29): External V
CC
Input. When EXTV
CC
ex-
ceeds 6.4V (typical), INTV
CC
will be powered from this
pin. When EXTV
CC
is lower than 6.4V, the INTV
CC
will be
powered from V
INCHIP
.
CSPOUT (Pin 30): The (+) Input to the V
OUT
Current Moni-
tor Amplifier. This pin and the CSNOUT pin measure the
voltage across the sense resistor, R
SENSE2
, to provide the
V
OUT
current signals. Connect this pin to V
OUT
when not
in use. See Applications Information section for proper
use of this pin.
CSNOUT (Pin 31): The (–) Input to the V
OUT
Current Monitor
Amplifier. Connect this pin to V
OUT
when not in use. See
Applications Information section for proper use of this pin.
CSNIN (Pin 32): The (–) Input to the V
IN
Current Monitor
Amplifier. This pin and the CSPIN pin measure the voltage
across the sense resistor, R
SENSE1
, to provide the V
IN
cur-
rent signals. Connect this pin to V
IN
when not in use. See
Applications Information section for proper use of this pin.
CSPIN (Pin 33): The (+) Input to the V
IN
Current Monitor
Amplifier. Connect this pin to V
IN
when not in use. See
Applications Information section for proper use of this pin.
V
INCHIP
(Pin 34): Main Input Supply Pin for the LT8708.
It must be locally bypassed to ground.
INTV
CC
(Pin 35): 6.3V Regulator Output. Must be connected
to the GATEV
CC
pin. INTV
CC
is powered from EXTV
CC
when
the EXTV
CC
voltage is higher than 6.4V, otherwise INTV
CC
is powered from V
INCHIP
. Bypass this pin to ground with
a minimum 4.7μF ceramic capacitor.
SWEN (Pin 36): Switching Regulator Enable Pin. Tie high
through a resistor to enable the switching. Ground to dis-
able switching. This pin is pulled down during shutdown,
a thermal lockout or when an internal UVLO (undervoltage
lockout) is detected. Don’t float this pin. See the Start-Up:
SWEN Pin section for more details.
MODE (Pin 37): Conduction Mode Select Pin. The voltage
applied to this pin sets the conduction mode of the control-
ler. Apply less than 0.4V to enable continuous conduction
mode (CCM). Apply 0.8V to 1.2V to enable the hybrid
conduction mode (HCM). Apply 1.6V to 2.0V to enable
the discontinuous conduction mode (DCM). Apply more
than 2.4V to enable Burst Mode operation.
IMON_OP (Pin 38): Positive V
OUT
Current Monitor and
Limit Pin. The current out of this pin is 20μA plus a cur-
rent proportional to the positive average V
OUT
current.
IMON_OP also connects to error amplifier EA6 and can
be used to limit the maximum positive V
OUT
current. See
the Applications Information section for more information.
IMON_ON (Pin 39): Negative V
OUT
Current Monitor and
Limit Pin. The current out of this pin is 20μA plus a cur-
rent proportional to the negative average V
OUT
current.
IMON_ON also connects to error amplifier EA2 and can
be used to limit the maximum negative V
OUT
current. See
the Applications Information section for more information.
LDO33 (Pin 40): 3.3V Regulator Output. Bypass this pin
to ground with a minimum 0.1μF ceramic capacitor.
GND (Pin 15, Exposed Pad Pin 41): Ground. Tie directly
to local ground plane.
PIN FUNCTIONS
