Datasheet

LT3519/LT3519-1/LT3519-2
7
3519fa
BLOCK DIAGRAM
–
+
+
–
+
–
+
+
+
–
+
+
–
A1
–
+
A4
1.1V
1.22V
1.22V
–
+
1.16V
FB
GND
1, 8, 9, 16
OPENLED
2V
2.2μA
Q3
CTRL
100mV
ISP
R
SENSE
LED ARRAY
ISN
s4
A2
A3
R
C
R
S
3519 BD
C
C
C
OUT
C
IN
ERROR
AMPLIFIER
PWM
COMPARATOR
11
14
FB
13
SHDN/UVLO
4
V
IN
V
REF
15
2
12
PWM
PWM
3
CATHODE
D1
10
ANODE
7
SW
V
IN
V
IN
L1
6
5
G1
G3
MAIN SWITCH
DRIVER
S
RQ
BANDGAP
AND
BIAS
G4
V
IN
140μA
–
+
Q2
–
+
RAMP
GENERATOR
OSCILLATOR
A5
Q1
MAIN
SWITCH
A6
G2
Q4
R1
R2
92k
I
Q4
NOTE: THE MAXIMUM ALLOWED Q4 COLLECTOR CURRENT I
Q4
IS 2mA.