ltc3526lb-2 Linear Technology Corporation, ltc3526lb-2 Datasheet - Page 7

• Manufacturer Part Number: ltc3526lb-2
• Description: Ltc3526l-2/ltc3526lb-2 - 550ma 2mhz Synchronous Step-up Dc/dc Converters In 2mm ? 2mm Dfn
• Manufacturer: Linear Technology Corporation

TO 5V
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
MOSFET switch and P-channel MOSFET synchronous recti-
fier, the LTC3526L-2 achieves high efficiency over a wide
0.8V
V
IN
C
2.2µF
IN
DS(ON)
4
SHDN
and low gate charge internal N-channel
4M
(Refer to Block Diagram)
SHUTDOWN
UVLO
V
REF
SHUTDOWN
THERMAL
START-UP
ANTI-RING
2MHz
OSC
V
SHUTDOWN
REF
V
OUT
V
BEST
CLK
TSD
3
V
IN
V
B
GATE DRIVERS
CONDUCTION
ANTI-CROSS
LOGIC
AND
2.2µH
L1
EXPOSED
V
SEL
PAD
7
I
I
ZERO
PK
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
enters normal operating mode. When the output voltage
COMP
CONTROL
I
GND
PK
MODE
WAKE
1
2
SW
LTC3526L-2/LTC3526LB-2
–
+
SLOPE
COMP
CLAMP
IN
SWITCH
–
WELL
or V
C
SS
+
I
COMP
OUT
ZERO
SLEEP COMP
ERROR AMP
exceeds 1.3V typical, the IC
+
–
V
REF
V
OUT
3526lb2 BD
FB
6
5
R2
R1
3526lb2fa
C
4.7µF
V
1.5V
TO 5.25V
OUT
OUT