DEMO CIRCUIT 1280
LT3471EDD
QUICK START GUIDE
LT3471EDD
Dual 1.3A, 1.2MHz Boost/Inverter in 3mmx3mm
DFN
DESCRIPTION
Demonstration circuit 1280A is a dual output con-
verter featuring the LT3471EDD in Boost and In-
verter configurations. Both converters are powered
from the same 4.5V to 10V input source. The
Boost converter puts out 12V at 300mA and the
Inverter -12V at 200mA. The demo circuit dem-
onstrates small size and low component count.
The LT3471 operates with inputs as high as 16V
but in this demo board the input is limited by the
magnitude of the Boost output. In a Boost con-
verter the input needs to be less than the output.
The DC1280A is designed so that the Inverting
converter can easily be configured as a Boost. In-
structions are included in the schematic.
Both circuits are designed to demonstrate the soft
start feature, advantages of the 1.2MHz switching
frequency and the internal 42V/1.3A switches.
Both outputs on this demo board can be modified
for higher voltages. These circuits are intended for
space-conscious applications such as digital cam-
eras, cellular phones, palmtop computers PC
cards, miniature disk drives, xDSL power supplies,
flash memory products, local 5V or 12V supplies
and LCD displays.
Design files for this circuit board are available.
Call the LTC factory.
L
, LTC, LTM, LT, Burst Mode, OPTI-LOOP, Over-The-Top and PolyPhase are
registered trademarks of Linear Technology Corporation. Adaptive Power, C-Load,
DirectSense, Easy Drive, FilterCAD, Hot Swap, LinearView, µModule, Micropower
SwitcherCAD, Multimode Dimming, No Latency , No Latency Delta-Sigma, No
R
SENSE
, Operational Filter, PanelProtect, PowerPath, PowerSOT, SmartStart,
SoftSpan, Stage Shedding, SwitcherCAD, ThinSOT, UltraFast and VLDO are
trademarks of Linear Technology Corporation. Other product names may be trade-
marks of the companies that manufacture the products.
PERFORMANCE SUMMARY FOR BOOST CONVERTER
SYMBOL
V
IN
V
OUT
RIPPLE
EFFICIENCY
Specifications are at TA = 25°
C
MIN
4.5
11.64
TYP
12
40
84
MAX
10
12.36
UNITS
V
V
mV
%
PARAMETER
Input Supply Range
Output Voltage Range
CONDITIONS
V
IN
= 4.5V, I
LOAD
= 300mA
V
IN
= 4.5V, I
LOAD
= 300mA
V
IN
= 4.5V, I
LOAD
= 300mA
PERFORMANCE SUMMARY FOR INVERTING REGULATOR
TA = 25°
C
SYMBOL
V
IN
V
OUT
RIPPLE
EFFICIENCY
Specifications are at
PARAMETER
Input Supply Range
Output Voltage Range
CONDITIONS
V
IN
= 4.5V, I
LOAD
= 200mA
V
IN
= 4.5V, I
LOAD
= 200mA
V
IN
= 4.5V, I
LOAD
= 200mA
MIN
4.5
-11.64
TYP
-12
10
74
MAX
12
-12.36
UNITS
V
V
mV
%
QUICK START PROCEDURE
Demonstration circuit 1280 is easy to set up to
evaluate the performance of the LT3471EDD. Re-
fer to Figure 1 for proper measurement equipment
setup and follow the procedure below:
1
LT3471EDD
NOTE.
When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscilloscope
probe. Measure the input or output voltage ripple by touching the
probe tip directly across the Vin or Vout and GND terminals. See
Figure 2 for proper scope probe technique.
4.
Check for the proper output voltages.
NOTE.
If there is no output, temporarily disconnect the load to
make sure that the load is not set too high.
1.
Place jumpers in the following positions:
JP1
ON
JP2
ON
2.
With power off, connect the input power supply
(4.5V to 10V) to Vin and GND.
3.
Turn on the power at the input.
5.
Once the proper output voltages are estab-
lished, adjust the loads within the operating
range and observe the output voltage regula-
tion, ripple voltages, efficiency and other pa-
rameters.
Figure 1. Proper Measurement Equipment Setup for DC1280A
2
RF/Wirelessly
京公网安备 11010802033920号
EEWORLD
