LTC3105_15 Datasheet, PDF (1/18 Pages) Linear Technology – 400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up

LTC3105
400mA Step-Up DC/DC
Converter with Maximum Power
Point Control and 250mV Start-Up
FEATURES
n _{Low Start-Up Voltage: 250mV}
n _{Maximum Power Point Control}
n _{Wide VIN Range: 225mV to 5V}
n _{Auxiliary 6mA LDO Regulator}
n _{Burst Mode}^® _{Operation: IQ = 24µA}
n _{Output Disconnect and Inrush Current Limiting}
n _{VIN > VOUT Operation}
n _{Antiringing Control}
n _{Soft Start}
n _{Automatic Power Adjust}
n _{Power Good Indicator}
n _{10-Lead 3mm × 3mm × 0.75mm DFN and 12-Lead}
MSOP Packages
APPLICATIONS
n _{Solar Powered Battery/Supercapacitor Chargers}
n _{Energy Harvesting}
n _{Remote Industrial Sensors}
n _{Low Power Wireless Transmitters}
n _{Cell Phone, MP3, PMP and GPS Accessory Chargers}
DESCRIPTION
The LTC^®3105 is a high efficiency step-up DC/DC converter
that can operate from input voltages as low as 225mV. A
250mV start-up capability and integrated maximum power
point controller (MPPC) enable operation directly from low
voltage, high impedance alternative power sources such as
photovoltaic cells, TEGs (thermoelectric generators) and
fuel cells. A user programmable MPPC set point maximizes
the energy that can be extracted from any power source.
Burst Mode operation, with a proprietary self adjusting
peak current, optimizes converter efficiency and output
voltage ripple over all operating conditions.
The AUX powered 6mA LDO provides a regulated rail for
external microcontrollers and sensors while the main
output is charging. In shutdown, I_Q is reduced to 10µA
and integrated thermal shutdown offers protection from
overtemperature faults. The LTC3105 is offered in 10-lead
3mm × 3mm × 0.75mm DFN and 12-lead MSOP packages.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATION
Single Photovoltaic Cell Li-Ion Trickle Charger
10µH
225mV TO 5V
+
PHOTOVOLTAIC
CELL
–
V_IN
SW
10µF
V_OUT
LTC3105
OFF _ON
40.2k
MPPC
SHDN
AUX
FB
PGOOD
LDO
FBLDO
1µF
GND
1020k
332k
2.2V
10µF
V_OUT
4.1V
Li-Ion
4.7µF
3105 TA01a
Output Current vs Input Voltage
80
MPPC DISABLED
70
60
V_OUT = 3.3V
50
V_OUT = 4.2V
40
V_OUT = 5V
30
20
10
0
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
INPUT VOLTAGE (V)
3105 TA01b
3105fa
1