Datasheet

LTC3526L-2/LTC3526LB-2
7
3526lb2fa
block DiagraM
3
3
+
–
+
–
GATE DRIVERS
AND
ANTI-CROSS
CONDUCTION
LOGIC
CLK
I
PK
I
PK
COMP
SLOPE
COMP
I
ZERO
COMP
ERROR AMP
SLEEP COMP
I
ZERO
WAKE
EXPOSED
PAD
+
–
WELL
SWITCH
MODE
CONTROL
UVLO
V
REF
V
REF
4M
SHDN
V
BEST
START-UP
2MHz
OSC
TSD
THERMAL
SHUTDOWN
SHUTDOWN
ANTI-RING
V
SEL
V
IN
1
6
SW
V
OUT
L1
2.2µH
V
B
SHUTDOWN
CLAMP
C
SS
V
REF
V
OUT
5
7
GND
3526lb2 BD
2
FB
R2
C
OUT
4.7µF
V
OUT
1.5V
TO 5.25V
R1
4
C
IN
2.2µF
V
IN
0.8V
TO 5V
(Refer to Block Diagram)
operaTion
The LTC3526L-2/LTC3526LB-2 are 2MHz synchronous
boost converters housed in a 6-lead 2mm × 2mm DFN
package. With a guaranteed ability to start up and oper-
ate from inputs less than 0.8V, this device features fixed
frequency, current mode PWM control for exceptional line
and load regulation. The current mode architecture with
adaptive slope compensation provides excellent transient
load response, requiring minimal output filtering. Internal
soft-start and internal loop compensation simplifies the
design process while minimizing the number of external
components.
With its low R
DS(ON)
and low gate charge internal N-channel
MOSFET switch and P-channel MOSFET synchronous recti-
fier, the LTC3526L-2 achieves high efficiency over a wide
range of load currents. Burst Mode operation maintains
high efficiency at very light loads, reducing the quiescent
current to just 9µA. Operation can be best understood by
referring to the Block Diagram.
LOW VOLTAGE START-UP
The LTC3526L-2/LTC3526LB-2 include an independent
start-up oscillator designed to start up at an input voltage
of 0.68V (typical). Soft-start and inrush current limiting
are provided during start-up, as well as normal mode.
When either V
IN
or V
OUT
exceeds 1.3V typical, the IC
enters normal operating mode. When the output voltage