Linear Technology LTC3129-1 Manual

FeaTures
Regulates V Above, Below or Equal to V
n
OUT
Wide V Range: 2.42V to 15V, 1.92V to 15V After
n IN
Start-Up (Bootstrapped)
Fixed Output Voltage with Eight User-Selectable
n
Settings from 2.5V to 15V
200mA Output Current in Buck Mode
n
Single Inductor
n
1.3µA Quiescent Current
n
Programmable Maximum Power Point Control
n
1.2MHz Ultralow Noise PWM
n
Current Mode Control
n
Pin Selectable Burst Mode
n
Up to 95% Efficiency
n
Accurate RUN Pin Threshold
n
Power Good Indicator
n
10nA Shutdown Current
n
Thermally Enhanced 3mm × 3mm QFN and
n
16-Lead MSOP Packages
applicaTions
Industrial Wireless Sensor Nodes
n
Post-Regulator for Harvested Energy
n
Solar Panel Post-Regulator/Charger
n
Intrinsically Safe Power Supplies
n
Wireless Microphones
n
Avionics-Grade Wireless Headsets
n
Typical applicaTion
V
IN
2.42V TO 15V
10µF
V
CC
AA OR AAA
BATTERIES
IN
Operation
®
22nF 22nF
10µH
BST1 SW1 SW2 BST2
V V
IN OUT
10µF
LTC3129-1
RUN
MPPC PGOOD
PWM
VS1 V
CC
VS2
VS3
2.2µF
GND PGND
31291 TA01a
For more information
15V, 200mA Synchronous
Buck-Boost DC/DC Converter
with 1.3µA Quiescent Current
DescripTion
The LTC 3129-1
®
DC/DC converter with a wide V
includes an accurate RUN pin threshold to allow predict-
able regulator turn-on and a maximum power point control
(MPPC) capability that ensures maximum power extraction
from non-ideal power sources such as photovoltaic panels.
The LTC3129-1 employs an ultralow noise, 1.2MHz PWM
switching architecture that minimizes solution footprint by
allowing the use of tiny, low profile inductors and ceramic
capacitors. Built-in loop compensation and soft-start
simplify the design. For high efficiency operation at light
loads, automatic Burst Mode operation can be selected,
reducing the quiescent current to just 1.3µA. To further
reduce part count and improve light load efficiency, the
LTC3129-1 includes an internal voltage divider to provide
eight selectable fixed output voltages.
Additional features include a power good output, less than
10nA of shutdown current and thermal shutdown.
The LTC3129-1 is available in thermally enhanced
3mm × 3mm QFN and 16-lead MSOP packages. For an
adjustable output voltage, see the functionally equivalent
LTC3129.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective owners.
V
OUT
5V AT
100mA V < V
IN OUT
200mA V > V
IN OUT
www.linear.com/LTC3129-1
LTC3129-1
is a high efficiency, 200mA buck-boost
and V
IN
Efficiency and Power Loss vs Load
100
EFFICIENCY
90
80
70
60
50
POWER LOSS
40
30
V
IN
20
V
IN
V
10
IN
V
V = 5V
IN
OUT
0
0.01 0.1 1 10 100
OUTPUT CURRENT (mA)
range. It
OUT
1000
100
10
1
= 2.5V
0.1
= 3.6V
= 5V
= 15V
0.01
1000
3129 TA01b
31291fc
1