LTC3453_15 Datasheet, PDF (5/12 Pages) Linear Technology – Synchronous Buck-Boost High Power White LED Driver

BLOCK DIAGRA
OPTIONAL
LTC3453
OPTIONAL
V_IN
2.7V TO 5.5V
PV_IN
16
1 ^VIN
UNDERVOLTAGE
LOCKOUT
UV
SWITCH A
15
SW1
14
SW2
SWITCH D
SWITCH B
GATE
DRIVERS
AND
ANTICROSS-
CONDUCTION
SWITCH C
OVERTEMP
PROTECTION
BANDGAP
REFERENCE
OT
1.23V
1612mA
FORWARD
CURRENT
LIMIT
+
–
REVERSE
CURRENT
LIMIT
200mA
+
LOGIC
–
AB PWM
COMPARATOR
UV
CD PWM
COMPARATOR
OT
V_C
12
I_SET1
3
R_ISET1
I_SET2
10
R_ISET2
EN1
2
EN2
11
V_BIAS
V_FB
LED CURRENT
SETTING AMP 1
800mV
+
–
1MHz
OSCILLATOR
MAIN
–
ERROR AMP
SAFETY
ERROR AMP
+
1.23V
SOFT
START
CLAMP
∑
I_LED
384
V_OUT
1.23V
327k
123k
800mV
LED CURRENT
+ ^{SETTING AMP 2}
I_LED
384
–
SHUTDOWN
GND
5
GND
8
EXPOSED PAD (PGND)
17
V_OUT
13
V_OUT
LED1
4
LED
DETECT
LED2
6
LED
DETECT
LED3
7
LED
DETECT
LED4
9
LED
DETECT
OR
4
6
7
9
3453 BD
3453fa
5