DC1447A - Demo Manual

DEMO CIRCUIT 1447
QUICK START GUIDE
LT3082EDD
DESCRIPTION
Demonstration circuit 1447A is an adjustable 200mA
linear regulator featuring LT®3082. Architected as a
precision current source and voltage follower, it allows this new regulator to be used in many applications with adjustability to zero output. Also LT3082
withstands reverse input voltages and reverse output-to-input voltages without reverse-current flow.
A key feature of the LT3082 is the capability to supply a wide output voltage range. By using a reference
current through a single resistor, the output voltage
can be programmed to any level between zero and
38.5V. DC1447A is capable of delivering up to
200mA output current. Therefore, the DC1447A can
be used as an all surface mount linear regulator, post
regulator for switching supply, low parts count variable voltage supply, low output voltage power supply
or battery powered regulator.
Internal protection circuitry includes reverse-battery
and reverse-current protection, current limiting and
thermal limiting.
LT3082 regulator is offered in the thermally enhanced 8-lead TSOT-23, 3-lead SOT-223 and 8-lead
3mm× 3mm DFN packages.
The LT3082 datasheet gives a complete description
of the part, operation and application information.
The datasheet should be read in conjunction with this
quick start guide for working on or modifying the
demo circuit 1447A.
Design files for this circuit board are available.
Call the LTC factory.
, LTC, LTM, LT and uModule are registered trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners.
Table 1. Performance Summary ( TA = 25oC )
PARAMETER
CONDITION
VALUE
Minimum Vin Voltage
Vout=1.2V
2.8V
Maximum Vin Voltage
Output Voltage
35V
JP1, Vout=1.2V
1.2V ±3%
JP1, Vout=1.8V
1.8V ±3%
JP1, Vout=2.5V
2.5V ±3%
JP1, Vout=3.3V
3.3V ±3%
JP1, Vout=5.0V
5.0V ±3%
Minimum Output Current
0.5mA
Maximum Output Current
200mA
1
DEMO CIRCUIT 1447
QUICK START GUIDE
QUICK START PROCEDURE
The DC1447A is easy to set up to evaluate the performance of the LT3082. Refer to Figure 1. for
proper measurement equipment setup and following the procedures below:
2.
Assume 1.2V is the desired output. Apply
2.8V across Vin (to Gnd). Draw 200mA of
load current. The measured Vout should be
1.2V ± 3% (1.174V to 1.246V).
1.
3.
Vary Vin from 2.8V to 35V and the load current from 0.5mA to 200mA. Vout should
measure 1.2V ± 3% (1.174V to 1.246V).
Before proceeding to test, use jumper JP1
for the desired output voltage (1.2V, 1.8V,
2.5V, 3.3V or 5.0V). If the output voltage is
different from the above values, use the
USER option and install R6. Select R6 according to the following equation: R6 = VOUT .
Note: Make sure the power dissipation is limited
below the thermal limit.
10µA
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple
2
DEMO CIRCUIT 1447
QUICK START GUIDE
3
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