Datasheet

6
LT3473/LT3473A
3473f
BLOCK DIAGRA
W
Figure 1. LT3473 Block Diagram
Σ
+
–
+
–
+
A2
ENABLE
ERROR
AMPLIFIER
V
REF
1.25V
A3
Q1
COMPARATOR
POWER SECTION
DRIVER
1.2MHz
OSCILLATOR
RAMP
GENERATOR
S
PNP
DRIVER
Q
BTH
V
C
FB
100mV
Q5
R
–
+
A1
–
+
+
g
m
4
CTRL
SW
Q2
CAP
8
1
OUT
2
SHDN
6
V
IN
7
PGOOD
5
GND
9
––
+
A4
3437 F01
3
Figure 2. LT3473A Block Diagram
Σ
+
–
+
–
+
A2
ENABLE
ERROR
AMPLIFIER
V
REF
1.25V
A3
Q1
Q3
COMPARATOR
POWER SECTION
DRIVER
1.2MHz
OSCILLATOR
RAMP
GENERATOR
S
PNP
DRIVER
Q
BTH
V
C
FB
100mV
Q5
R
–
+
A1
–
+
+
g
m
7
CTRL
SW
Q2
CAP
12
1
OUT
2
SHDN
10
V
IN
11
PGOOD
9
GND
13
––
+
A4
NB1
3
NE1
NE2
3437 F02
4
Q4
NB2
5
6
8