Datasheet

8
LT1505
1505fc
BLOCK DIAGRAM
W
–
+
–
+
A2
A3
7V
A1
2
50k
C3
4.7µF
L1
10µH
R
S1
VR
S1
+–
TGATE
V
CC
3
SW
1
BOOST
M1
M2
+
2.5V
BGATE
+
9.1V
12.6V
BATTERY
+
+
–
+
A4
A6
4V
SW
+
–
+
–
+
A12
0.02V
PWM
SLOPE COMP
Q2
Q1
CA1
–
+
–
+
–
+
A11
I
PROG
VR
S1
+
–
+
E4
1.3V
4U
+
50k
A5
A9
A7
A8
26
GBIAS
27
BGATE
28
PGND
22
SPIN
R
S3
21
SENSE
23
BAT
20
BAT2
16
3CELL
17
V
FB
14
4.1V
R4
50.55k
R5
21k
15
4.2V
R6
0.33k
R7
12.3k
R
PROG
C
PROG
V
REF
2.465V
V
IN
V
CC
R1
1k
R2
R3
R8
75k
25
BOOSTC
C2
1µF
SR
SHUTDOWN
A10
I
VA
V
REF
I
PROG
B1
–
+
E6
–
+
CA2
C1
R
S2
I
BAT
–
+
–
+
CL1*
*LT1505 ONLY. SEE PIN FUNCTIONS
FOR LT1505-1 CONNECTIONS
COMP1
1505 BD
PROG
V
C
9
CLP
92mV
10
111918
CLN
SYSTEM
LOAD
AGND
6
Q3
VA
OSC
200k
ONE
SHOT
SYNC
4
FLAG
13
5
SHDN
–
+
E5
7V
+
GBIAS
BAT
3.3V
I
PROG
+
–
+
E1
SHUTDOWN
V
CC
V
IN
24
UV
V
CC
7
8
–
+
E2
6.7V
+
+
–
+
E8
6.7V
0.2V
+
E3
A13
Q4
7.8V
V
CC
INFET
V
CC
V
IN
CAP
12
E7
+
R
S
I
VA
4
(LT1505)