LTC3532_15 Datasheet, PDF (1/16 Pages) Linear Technology – Micropower Synchronous Buck-Boost DC/DC Converter

LTC3532
Micropower Synchronous
Buck-Boost DC/DC Converter
FEATURES
DESCRIPTIO
■ _{Single Inductor}
■ _{Regulated Output with Input Voltages Above, Below}
or Equal to the Output
■ _{Wide VIN Range: 2.4V to 5.5V}
■ _{VOUT Range: 2.4V to 5.25V}
■ _{Up to 500mA Peak Output Current}
■ _{Synchronous Rectification: Up to 95% Efficiency}
■ _{Manual or Programmable Automatic Burst Mode}^®
Operation
■ _{Output Disconnect in Shutdown}
■ _{Programmable Oscillator: 300kHz to 2MHz}
■ _{Pin Compatible with LTC3440}
■ _{Small Thermally Enhanced 10-Lead (3mm × 3mm)}
DFN and 10-Lead MSOP Packages
U
APPLICATIO S
■ _{Miniature Hard Disk Drive Power Supply}
■ _{MP3 Players}
■ _{Handheld Instruments}
■ _{Digital Cameras}
■ _{Handheld Terminals}
The LTC^®3532 is a high efficiency, fixed frequency, buck-
boost DC/DC converter that operates from input voltages
above, below or equal to the output voltage. The topology
incorporated in the IC provides a continuous transfer
function through all operating modes, making the product
ideal for single lithium-ion, multicell alkaline or NiMH ap-
plications where the output voltage is within the battery
voltage range.
The device includes two 0.36Ω N-channel MOSFET
switches and two 0.42Ω P-channel switches. Switching
frequencies up to 2MHz are programmed with an external
resistor. Quiescent current is only 35μA in Burst Mode
operation, maximizing battery life in portable applica-
tions. Automatic Burst Mode operation allows the user
to program the load current for Burst Mode operation or
to control it manually.
Other features include a 1μA shutdown, soft-start control,
thermal shutdown, and peak current limit. The LTC3532 is
available in a low profile (0.75mm) 10-lead (3mm × 3mm)
DFN and 10-lead MSOP packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
Miniature Hard Disk Drive Power Supply
V_IN
Li-Ion
2.5V TO 4.2V
200k
4.7μF
4.7μH
SW1
V_IN
SHDN/SS _LTC3532
BURST
R_T
43.2k
0.01μF
V_OUT
3.3V
100mA
TO 500mA
V_OUT
200mV/DIV
SW2
340k 1k
(PEAK)
V_OUT
FB
12.1k
V_C
220pF
GND
33pF
200k
10μF
I_LOAD
100mA/DIV
100μs/DIV
V_IN = 3V
V_OUT = 3.3V
I_LOAD = 50mA TO 300mA
3532 TA01b
3532 TA01
3532fc
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