Linear Technology 813 Operating and maintenance instructions

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 813
HIGH VOLTAGE MICROPOWER VOLTAGE REGULATOR
1
LT3013
DESCRIPTION
Demonstration circuit 813 is a high voltage micro-
power voltage regulator using the LT3013 low drop-
out linear regulator, which comes in a low-profile 12-
pin DFN package. DC813 has an input voltage range
from 3V to 80V, an output voltage range between
1.24V and 60V, and is capable of delivering 250 mA
max. The DC supply current is typically only 1 uA in
shutdown. DC813 is installed with ceramic capaci-
tors, because of its ability to maintain stability with
ceramic output capacitors. Due to its high input volt-
age range, the DC813 voltage regulator is ideally
suited for automotive and industrial applications.
Design files for this circuit board are available. Call
the LTC factory.
LTC is a trademark of Linear Technology Corporation
QUICK START PROCEDURE
DC813 is easy to set up to evaluate the performance
of the LT3013. For proper measurement equipment
configuration, set up the circuit according to the dia-
gram in Figure 1.
Please follow the procedure outlined below for proper
operation.
1. Before proceeding to test, insert a shunt into
the OFF position of jumper JP1, and insert a
shunt into jumper JP2, the 3.3V option.
2. Apply 5V across Vin (to GND). Insert the
jumper JP1 shunt into the ON position. Draw
1 mA of load current. Measure Vout; it should
be 3.3V +/- 2.5% (3.21V to 3.39V).
3. Vary the input voltage from 5V to 80V and the
load current from no load to 250 mA. Vout
should measure 3.3V +/- 5% (3.13V to
3.47V).
Note: Be aware of the power dissipated by the
LT3013, due to its high input voltage capabil-
ity. Consequently, take care to stay under the
maximum junction temperature, 125 deg.C,
when operating the LT3013.
4. Insert the jumper JP1 shunt into the OFF posi-
tion and move the shunt in jumper JP2 into
the 5V output voltage option, and repeat the
test. Re-insert jumper JP1 shunt into the ON
position. Just as in the 3.3 Vout test, the 5V
output voltage should read Vout +/- 2.5% tol-
erance under static line and load conditions,
and +/- 5% tolerance under dynamic line and
load conditions.
5. When finished evaluating, insert jumper JP1
shunt into the OFF position.
Warning - If long leads are used to power the demo circuit, the input voltage at the part could “ring”. This ring-
ing could affect the operation of the circuit or even exceed the maximum voltage rating of the IC. To eliminate
this, insert a small aluminum electrolytic capacitor (for instance, a Sanyo cap., part # 100CV10BS) on the pads
between the input power and return terminals on the bottom of the demo board. The (greater) ESR of the alu-
minum electrolytic capacitor will dampen the (possible) ringing voltage due to the use of long input leads. On a
normal, typical PCB, with short traces, the capacitor is not needed.

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 813
HIGH VOLTAGE MICROPOWER VOLTAGE REGULATOR
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Figure 2. Measuring Input or Output Voltage Ripple
Figure1. Proper Measurement Equipment Setup

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 813
HIGH VOLTAGE MICROPOWER VOLTAGE REGULATOR
3