LTC3785-1 Linear Technology, LTC3785-1 Datasheet - Page 7

• Manufacturer Part Number: LTC3785-1
• Description: Buck-Boost Controller
• Manufacturer: Linear Technology

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BLOCK DIAGRAM
R2
R
C
V
V
ILSET
R
OUT
OUT
SS
T
R1
C
P1
1
4
3
2
7
8
5
RUN/SS
V
FB
V
RT
MODE
I
LSET
SENSE
C
1.5V
1.225V
1/2 LIMIT AT V
V
1.225V
BE
–
+
1μA
+
–
–
+
I
LIMIT
SET
1 = Burst Mode OPERATION
0 = FIXED FREQUENCY
I
SS
LIM(OUT)
2μA
OSC
–7.5%
OUT
7.5%
10μA MAX
I
LIM(OUT)
+
–
< 1V
RUN
I
I
LIM
MAX
FAULT
LOGIC
UVLO
+
–
–
+
COMP
UVLO
COMP
UV
OV
SD
BURST
LOGIC
UV
OV
TSD
+
–
1.225V
UV
OV
BURST
2.4V
REVERSE
PULSE
PULSE
DDRV
ADRV
BDRV
LIMIT
CDRV
I
I
SW1
SW2
LIMIT
MAX
V
9
REF
PGOOD
V = 60k/R
2.7V TO 10V
1/25k
(ZERO LIMIT FOR BURST)
DELAY
DELAY
BBM
SW1
BBM
SW2
V = 90k/R
ILSET
CURRENT LIMIT
4.5V REG
V
IN
GND/PGND
REVERSE
DISABLE
24
g
V
ILSET
25
IDEAL DIODE
m
TG1
BG1
TG2
BG2
IN
+
–
+
–
V
LOW
+
–
OUT
1X I
15mV
OR
LIMIT
V
REV
SAMPLED
–
+
X10
V
CHARGE PUMP
REV
+
–
CHARGE PUMP
100% DUTY
1.8V
100% DUTY
SAMPLED
0 = 15mV
1 = I
PGND
PGND
V
DRV
LIMIT
I
I
SVOUT
I
V
V
SSW1
V
SSW2
I
SW1
SW2
CCM
BST1
BST2
SVIN
BG1
BG2
TG1
TG2
V
DRV
CC
23
22
20
21
19
18
16
17
10
12
11
13
14
15
6
C
A
LTC3785-1
C
B
C
SW2
MA
MB
MD
MC
SW1
VCC
D1
OPT
D2
OPT
L1
37851 BD
37851f
C
V
C
7
OUT
OUT
IN