LT8611EUDDPBF Datasheet, PDF (10/24 Pages) Linear Dimensions Semiconductor – 42V, 2.5A Synchronous Step-Down Regulator with Current Sense and 2.5μA Quiescent Current

LT8611
Pin Functions
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.
Block Diagram
V_IN
V_IN
C_IN ^{5, 6}
INTERNAL 0.97V REF
R3
1V +
OPT
EN/UV
4
– SHDN
R4
OPT
PG
19
V_OUT
ERROR
±9%
AMP
++
–
C1 R1
R2
C_SS
(OPT)
R_T
FB
20
TR/SS
2
3 ^RT
1 ^SYNC
SHDN
TSD
INTV_CC UVLO
V_IN UVLO
2.2µA
GND
25
–
+
SLOPE COMP
OSCILLATOR
200kHz TO 2.2MHz
V_C
BURST
DETECT
3.4V
REG
SWITCH
LOGIC
AND
ANTI-
SHOOT
THROUGH
BIAS
18
INTV_{CC 17}
BST
6
M1
SW
13-15
M2
C_VCC
C_BST
L
SHDN
TSD
V_IN UVLO
1.0V
20R
1.4µA
PGND
7, 8
R _ISP
21
R _ISN
22
1×
C_F R_SEN
C_OUT
ICTRL
24
IMON
23
8611 BD
V_OUT
8611f
10