1
dc2397af
DEMO MANUAL DC2397A
DESCRIPTION
LTC3130EUD-1
25V, 600mA Buck-Boost DC/DC Converter
with 1.6
μ
A Quiescent Current
Demonstration circuit 2397A features the
, a
wide input voltage, wide output voltage operating range,
high efficiency, low noise monolithic DC/DC buck-boost
converter.
The LTC3130-1 has 4-pin selectable output voltages
and operates from input voltages of 2.4V to 25V. The
LTC3130-1 incorporates a proprietary low noise switching
algorithm which optimizes efficiency with input voltages
above, below, or equal to the output voltage and ensures
seamless transitions between operating modes.
The LTC3130-1’s user selectable output voltages are 1.8V,
3.3V, 5.0V and 12V. To set the desired output voltage on
the DC2397A, use the “V
OUT
JUMPER CONFIGURATION”
table on the front of the board to determine the jumper
settings for JP2 and JP3.
The DC2397A demo board has two user selectable oper-
ating modes: Burst Mode
®
operation and fixed frequency
PWM (JP1). In PWM Mode, the LTC3130-1 operates at
1.2MHz to allow high efficiency while minimizing the
solution footprint.
Internal compensation reduces footprint size by reducing
the number of external components. This also simplifies
the design process and reduces external component cost.
An accurate RUN threshold can be set to enable the
converter at a desired input voltage. The DC2397A demo
board is set up to use R2 in conjunction with R3 to set
this threshold. See the data sheet for details.
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.
PERFORMANCE SUMMARY
Maximum power point control (MPPC) allows for simple
optimization of power transfer between the converter
and a non-ideal supply such as a photovoltaic panel or
another high impedance source. The DC2397A demo board
can be set to operate in MPPC mode by setting jumper
JP4 to “ON”, removing R4 and populating R5 and R6. In
most applications this function can be realized, often with
better efficiency, by using the accurate RUN comparator
functionality. See the data sheet for details.
A PGOOD open-drain output is provided and is pulled
up to V
OUT
. This output asserts low when V
OUT
is below
regulation.
The LTC3130-1 allows the internal V
CC
rail to be fed
externally from the EXTV
CC
pin. In some applications the
efficiency of the converter can be improved by allowing
V
CC
to be back-fed from a supply, such as V
OUT
. Setting
the EXTV
CC
jumper (JP6) on the demo board to “EXT”
back-feeds V
CC
through EXTV
CC
from V
OUT
. Setting this
jumper to internal (“INT”) powers V
CC
off the V
IN
input.
See the data sheet for additional details.
The LTC3130/LTC3130-1 data sheet has detailed informa-
tion about the operation, specifications, and applications of
the device. The data sheet should be read in conjunction
with this quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2397A
Input Voltage Range
2.4V to 25V
V
OUT
1.8V, 3.3V, 5V, 12V
I
OUT
(see Note 1)
600mA
Efficiency
See Figure 1
Note 1:
The demo board output current is a function of V
IN
. Please refer to the data sheet for more information.
