DC1024A - Demo Manual

DEMO CIRCUIT 1024
LT3494START
AND LT3494A
QUICK
GUIDE
LT3494 and LT3494A
Micropower Low Noise Boost Converters
With Output Disconnect
DESCRIPTION
Demonstration circuits 1024A-A and
1024A-B are Micropower Low Noise
Boost Converters With Output Disconnect featuring the LT3494 and LT3494A
respectively. The demo circuits demonstrate small size and low component count in Boost configuration.
Both demo versions are designed to
convert a 3V-4.2V source to 15V. The
only difference is in the load capability. The 1024A–A supplies 17mA at
3Vin while the 1024A–B supplies
27mA, also at 3Vin. The LT3494 features integrated Schottky diode,
output disconnect function, dimming
control, output sense resistor and
non-audible
switching
frequency
over the entire load range. A 2-3%
improvement in efficiency can be
achieved by adding an external
CMDSH-3 diode. A place holder is
available on the back of the board.
These circuits are intended for
space-conscious applications such
as OLED power, MP3 Players, and Low
Noise Bias Supplies.
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 RSENSE, 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
trademarks of the companies that manufacture the products.
PERFORMANCE SUMMARY DC1024A-A
SYMBOL
VIN
VOUT
VOUT
VOUT
PARAMETER
Input Supply Range
Output Voltage Range
Output Voltage Range
Output Voltage Range
RIPPLE
EFFICIENCY Load at Vout
EFFICIENCY Load at VCAP
CONDITIONS
VIN
VIN
VIN
VIN
VIN
VIN
=
=
=
=
=
=
3V, ILOAD =
3.6V, ILOAD
4.2V, ILOAD
3.6V, ILOAD
3.6V, ILOAD
3.6V, ILOAD
17mA
= 25mA
= 32mA
= 25mA
= 25mA
= 25mA
PERFORMANCE SUMMARY DC1024A-B
SYMBOL
VIN
VOUT
VOUT
VOUT
PARAMETER
Input Supply Range
Output Voltage Range
Output Voltage Range
Output Voltage Range
RIPPLE
EFFICIENCY Load at Vout
EFFICIENCY Load at VCAP
Specifications are at TA = 25°C
=
=
=
=
=
=
3V, ILOAD =
3.6V, ILOAD
4.2V, ILOAD
3.6V, ILOAD
3.6V, ILOAD
3.6V, ILOAD
TYP
15
15
15
20
77
79
MAX
4.2
15.45
15.45
15.45
UNITS
V
V
V
V
mV
%
%
Specifications are at TA = 25°C
CONDITIONS
VIN
VIN
VIN
VIN
VIN
VIN
MIN
3
14.55
14.55
14.55
27mA
= 35mA
= 44mA
= 35mA
= 35mA
= 35mA
MIN
3
14.55
14.55
14.55
TYP
15
15
15
20
74
77
MAX
4.2
15.45
15.45
15.45
UNITS
V
V
V
V
mV
%
%
1
LT3494 AND LT3494A
QUICK START PROCEDURE
Demonstration circuit 1024 is easy to
set up to evaluate the performance of
the LT3494 and LT3494A. Refer to
Figure 1
for
proper
measurement
equipment setup and follow the procedure below:
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.
1. Place jumpers in the following positions:
JP1 Run
2. With power off, connect the input
power supply to Vin and GND.
2
3. Turn on the power at the input.
4. Check for the proper output voltages. Vout1 = 14.55V to 15.45V.
NOTE. If there is no output, temporarily
disconnect the load to make sure that the load
is not set too high.
5. Once the proper output voltage is
established, adjust the load within
the operating range and observe the
output voltage regulation, ripple
voltage, efficiency and other parameters.
LT3494 AND LT3494A
Figure 1. Proper Measurement Equipment Setup
GND
VIN
Figure 2. Measuring Input or Output Ripple
3
LT3494 AND LT3494A
Efficie ncy at 3.6Vin
80
Efficiency in %
78
76
LT3494
74
LT3494A
72
70
68
66
0.00
10.00
20.00
30.00
40.00
load in mA
Efficiency Comparison Between LT3494 and LT3494A
4
LT3494 AND LT3494A
5
Similar pages