Datasheet
LT8611
10
8611fa
For more information www.linear.com/LT8611
BLOCK DIAGRAM
ISN (Pin 22): Current Sense (–) Pin. This is the inverting
input to the current sense amplifier.
IMON (Pin 23): Proportional-to-Current Monitor Output.
This pin sources a voltage 20 times the voltage between
the ISP and ISN pins such that:
V
IMON
= 20 • (V
ISP
-V
ISN
).
IMON can source 200µA and sink 10µA. Float IMON if
unused.
ICTRL (Pin 24): Current Adjustment Pin. ICTRL adjusts
the maximum ISP-ISN drop before the LT8611 reduces
output current. Connect directly to INTV
CC
or float for
full-scale ISP-ISN threshold of 50mV or apply values
between GND and 1V to modulate current limit. There is
an internal 1.4µA pull-up current on this pin. Float or tie
to INTV
CC
when unused.
GND (Exposed Pad Pin 25): Ground. The exposed pad
must be connected to the negative terminal of the input
capacitor and soldered to the PCB in order to lower the
thermal resistance.
PIN FUNCTIONS
+
+
–
+
–
SLOPE COMP
INTERNAL 0.97V REF
OSCILLATOR
200kHz TO 2.2MHz
BURST
DETECT
3.4V
REG
M1
M2
C
BST
C
F
8611 BD
SW
L
BST
13-15
SWITCH
LOGIC
AND
ANTI-
SHOOT
THROUGH
ERROR
AMP
SHDN
±9%
V
C
SHDN
TSD
INTV
CC
UVLO
V
IN
UVLO
SHDN
TSD
V
IN
UVLO
EN/UV
1V
+
+
–
+
–
+
–
4
6
ISP
R
20R
V
OUT
R
SEN
ICTRL
1×
21
ISN
1.0V
R
22
2425
IMON
GND
23
INTV
CC
17
BIAS
18
PGND
7, 8
PG
19
FB
R1C1
R3
OPT
R4
OPT
R2
R
T
C
SS
(OPT)
V
OUT
20
TR/SS
2.2µA
2
RT
3
SYNC
1
V
IN
V
IN
C
IN
C
VCC
5, 6
1.4µA
C
OUT
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