1308AI Linear Technology Corporation, 1308AI Datasheet - Page 7

• Manufacturer Part Number: 1308AI
• Description: Lt1308b - Single Cell High Currentmicropower 600khz Boost Dc/dc Converter
• Manufacturer: Linear Technology Corporation

BLOCK DIAGRA S
V
OUT
R1
(EXTERNAL)
R2
(EXTERNAL)
V
OUT
FB
R1
(EXTERNAL)
R2
(EXTERNAL)
FB
V
V
IN
IN
11
12
FB
2
V
FB
6
2
IN
Q1
R5
40k
W
Q1
R5
40k
Q2
×10
R6
40k
Figure 2b. LT1308A/LT1308B Block Diagram (TSSOP Package)
R3
30k
R4
140k
Figure 2a. LT1308A/LT1308B Block Diagram (SO-8 Package)
Q2
×10
V
R6
40k
R3
30k
R4
140k
IN
+
–
OSCILLATOR
GENERATOR
600kHz
RAMP
g
AMPLIFIER
V
m
IN
ERROR
–
+
OSCILLATOR
GENERATOR
600kHz
RAMP
g
AMPLIFIER
m
ERROR
*HYSTERESIS IN LT1308A ONLY
Q4
V
Σ
IN
*HYSTERESIS IN LT1308A ONLY
+
+
BIAS
Q4
V
V
Σ
IN
1
C
+
+
BIAS
V
+
–
–
+
1
C
COMPARATOR
+
–
–
+
*
A1
A2
2V
COMPARATOR
BE
*
A1
A2
2V
BE
ENABLE
200mV
R
ENABLE
FF
S
200mV
R
LBI
13
Q
FF
S
LBI
7
+
–
Q
LT1308A/LT1308B
SHUTDOWN
+
–
DRIVER
A = 3
A4
SHUTDOWN
+
–
DRIVER
A = 3
A4
+
–
SHDN
GND
LBO
SW
14
3
8
4
Q3
0.03Ω
GND
SHDN
SW
GND
LBO
SW
9
5
3
8
5
4
Q3
0.03Ω
GND
SW
10
6
1308 BD2a
GND
7
1308abfa
1308 BD2b
7