Datasheet

LT8705
30
8705fb
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applicaTions inForMaTion
–
+
–
+
EA2
IMON_IN
8705 F10
C
IMON_IN
R
IMON_IN
CSPIN
R
SENSE1
FROM DC
POWER SUPPLY
TO REMAINDER
OF SYSTEM
TO BOOST CAPACITOR
CHARGE CONTROL BLOCK
CSNIN
LT8705
INPUT
CURRENT
V
C
1.208V
FAULT
CONTROL
1.61V
–
+
g
m
= 1m
Ω
A7
Figure 10. Input Current Monitor and Limit
Figure 11. Output Current Monitor and Limit
–
+
–
+
EA1
IMON_OUT
8705 F11
C
IMON_OUT
R
IMON_OUT
CSPOUT
R
SENSE2
FROM
CONTROLLER
V
OUT
TO SYSTEM V
OUT
CSNOUT
LT8705
OUTPUT
CURRENT
V
C
1.208V
FAULT
CONTROL
1.61V
–
+
g
m
= 1m
Ω
A8
TO BOOST CAPACITOR
CHARGE CONTROL BLOCK
Input/Output Current Monitoring and Limiting
The LT8705 has independent input and output current
monitor circuits that can be used to monitor and/or limit
the respective currents. The current monitor circuits work
as shown in Figures 10 and 11.
As described in the Topside MOSFET Driver Supply sec
-
tion, the CSNIN and CSPOUT pins are also connected
to the Boost Capacitor Charge Control block (also see
Figure1) and can draw current in certain conditions. In
addition, all four of the current sense pins can draw bias
current under normal operating conditions. As such, do
not place resistors in series with any of the CSxIN or
CSxOUT pins.