Datasheet

LT3581
8
3581fa
For more information www.linear.com/LT3581
block DiagraM
FREQUENCY
FOLDBACK
RAMP
GENERATOR
COMPARATOR
DRIVER
DISABLE
SS
LDO
V
C
R
GATE
14.6k
14.6k
SR1
A3
SYNC CLKOUT
÷N
SS
SHDN
C
OUT1
SW1
SW2
FB
27mΩ
R
S
20mΩ
GND
R
T
RT
R
C
C
C
V
C
R
FB
DRIVER
D1
V
IN
SYNC
BLOCK
UVLO
R
S
Q
3581 BD
–
+
A4
Q2
+
–
TD ~ 30ns
VBE • 0.9
1.17V
45mV
L1
FB
∑
ADJUSTABLE
OSCILLATOR
–
+
–
+
A1
A3
C
SS
C
IN
1.33V
+
–
–
+
+
–
250k
2.1V
1.8V
50mV
SOFT-
START
STARTUP
AND FAULT
LOGIC
C
OUT2
V
OUT
V
IN
M1
GATE
OPTIONAL
SAMPLE MODE BLOCK
R
FAULT
FAULT
933µA
–
+
+ – + –
+
–
+
–
+
–
+
–
+
–
DIE TEMP
22V
MIN
165°C
V
IN
750mV
SW1
**
**SW OVERVOLTAGE PROTECTION IS NOT GUARANTEED TO PROTECT THE LT3581 DURING SW OVERVOLTAGE EVENTS
**
I
SW1
42V
MIN
42V
MIN
1.9A
MIN
SW2
SAMPLE
–
+
A2
1.215V
REFERENCE
Q1
Figure 1. Block Diagram