Datasheet

LTC3101
1
3101fb
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
Wide V
IN
, Multi-Output
DC/DC Converter and
PowerPath Controller
The LTC
®
3101 is a complete power management solution
for low power portable devices. It provides three high
effi ciency switching DC/DC converters which seamlessly
transition from battery to USB/wall adapter power when
available. A synchronous buck-boost regulator provides
complete fl exibility, allowing operation from a single
Li-Ion/Polymer battery, 2 to 3 AA cells, a USB port or any
other power source operating from 1.8V to 5.5V.
Two always-alive outputs, a 50mA LDO and a 200mA MAX
output that tracks the higher voltage input supply, provide
power for critical functions or additional external regula-
tors. Flash memory cards can be directly powered from
the protected 100mA Hot Swap output. Pushbutton control
logic and a programmable-duration microprocessor reset
generator simplify interfacing to a microprocessor while
internal sequencing and independent enable pins provide
exible power-up options. The LTC3101 is available in a low
profi le (0.75mm) 24-lead 4mm × 4mm QFN package.
Effi ciency vs V
BAT
n
Low Loss PowerPath™ Control: Seamless,
Automatic Transition from Battery to USB or
Wall Adapter Power
n
Wide V
IN
Range: 1.8V to 5.5V
n
Buck-Boost V
OUT
:
1.5V to 5.25V
n
Buck-Boost Generates 3.3V at 300mA for
V
IN
≥ 1.8V, 3.3V at 800mA for V
IN
≥ 3V
n
Dual 350mA Buck Regulators, V
OUT
:
0.6V to V
IN
n
38µA Quiescent Current in Burst Mode
®
Operation
n
1.8V, 50mA Always-On LDO
n
Protected 100mA Hot Swap™ Output
n
Pushbutton On/Off Control
n
Current Limited 200mA MAX
Output
n
Programmable Power-Up Sequencing
n
24-lead 4mm × 4mm × 0.75mm QFN Package
n
Ultra-Portable Digital Video Cameras
n
Personal Handheld GPS Navigators
n
Portable Medical Instruments
BAT1
USB1
C
RS
ENA1
ENA2
ENA3
PWRKEY
PWRON
PWM
PBSTAT
RESET
USB2
FB3
LDO
SW2
FB2
HSO
MAX
10µF
10µF
2 AA
CELLS
USB/WALL
ADAPTER
4.3V TO 5.5V
10µF
1M
V
OUT3
= 3.3V
300mA FOR V
IN
≥ 1.8V
800mA FOR V
IN
≥ 3V
221k
Hot Swap OUTPUT: 3.3V AT 100mA
TRACKING OUTPUT: 200mA
4.7µH
4.7µF
1.8V AT 50mA
V
OUT2
1.8V
350mA
V
OUT1
1.5V
350mA
10µF
221k
110k
4.7µH
SW1
FB1
10µF
3101 TA01a
221k
147k
4.7µH
0.1µF
ON/OFF
BAT2 SW3A
LTC3101
GND
µP
SW3B OUT3
DIS ENA
+
V
BAT
(V)
1.5
84
EFFICIENCY (%)
86
88
90
92
94
96
2.5 3.5 4.5 5.5
3101 TA01b
BUCK-BOOST
I
OUT
= 150mA
BUCK2
I
OUT
= 150mA
BUCK1
I
OUT
= 150mA
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and Hot Swap and PowerPath are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.

Summary of content (34 pages)