Datasheet

5
LT1302/LT1302-5
PI FU CTIO S
U
UU
SW (Pin 7): Switch Pin. Connect inductor and diode here.
Keep layout short and direct.
PGND (Pin 8): Power Ground. Pins 8 and 1 should be
connected under the package. In the SO package, pins 1
and 8 are thermally connected to the die. One square inch
of PCB copper provides an adequate heat sink for the
device.
Figure 2. LT1302 Block Diagram
1302 F02
–
+
–
+
–
+
V
OS

15mV
R2
C5
100pF
36mV
CMP1
OFF
V
IN
2 µA
ENABLE
A2
V
IN
C2
0.1µF
C1
V
IN
L1
SW
PGNDI
T
V
C
R3
22k
C4
0.01µF
GND
SHDN
SHUTDOWN
FB
ERROR
AMPLIFIER
HYSTERETIC
COMPARATOR
DRIVER
A1
4
3
5 8
7
21
1.24V
REFERENCE
220kHz
OSCILLATOR
300Ω 3.6k
Q3
R4
1.75Ω
R5
730Ω
V
IN
BIAS
R1
6
+
C3
D1
V
OUT
+
Q4
160X
A3
Q1 Q2
Q5
BLOCK DIAGRA SM
W