LTC3452 Datasheet, PDF (7/16 Pages) Linear Technology – Synchronous Buck-Boost MAIN/CAMERA White LED Driver

BLOCK DIAGRA
V_IN
2.7V TO 5.5V
V_IN
1
PV_IN
20
SW1 SW2
19
17
V_OUT
16
V_{C 15}
UNDERVOLTAGE
LOCKOUT
UV
SWITCH
A
SWITCH
D
SWITCH
SWITCH
OVERTEMPERATURE
PROTECTION
OT
B
C
GATE
DRIVERS
AND
ANTI-CROSS-
BANDGAP
REFERENCE
1.23V
FORWARD _CONDUCTION REVERSE
CURRENT
CURRENT
+
LIMIT
LIMIT
+
1600mA –
– ^200mA
AB PWM
COMPARATOR
+
LOGIC
CD PWM
COMPARATOR
+
–
UV
OT
–
1MHz
OSCILLATOR
V_BIAS
–
V_{FB +}
MAIN
ERROR AMP
1.23V
SAFETY
ERROR AMP
1.23V
–
V_OUT
327k
+
123k
SOFT-START
CLAMP
I_SETL
3
R_ISETL
EN_L 2
EN_H 14
I_SETH
13
R_ISETH
800mV
LOW POWER
LED CURRENT
SETTING AMP
+
–
SDL
800mV
HIGH POWER
LED CURRENT
SETTING AMP
+
–
SDH
I_MAXL
256
EXPONENTIAL
BRIGHTNESS
CONTROL
SHUTDOWN
CIRCUIT
8 LEVELS
SDL
SHUTDOWN
SDH
I_MAXH
768
9
11
18
21
GND
GND
PGND EXPOSED
PAD
LTC3452
V_OUT
4
LED
DETECT
LED_L1
5
LED
DETECT
LED_L2
6
LED
DETECT
LED_L3
7
LED
DETECT
LED_L4
8
LED
DETECT
LED_L5
LOW
POWER
LED
BANK
10
LED
DETECT
LED_H1
12
LED
DETECT
LED_H2
HIGH
POWER
LED
BANK
3452 BD
3452f
7