QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1388A
3µA QUIESCENT CURRENT, 20mA LINEAR REGULATOR
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LT3008EDC
DESCRIPTION
Demonstration circuit 1388A is an ultralow quiescent
current and low dropout voltage linear regulator fea-
turing LT®3008, which comes in an 8-lead TSOT23
or 2mmX2mm DFN package. The DC1388A has an
input voltage range from 2V to 45V, and is capable of
delivering up to 20mA output current. With the 3µA
quiescent current of the LT3008, the DC1388A is
ideal for supplying power to low current battery-
powered systems, keep-alive power supply and re-
mote monitoring utility meters and hotel door locks.
The LT3008 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 1388A.
Design files for this circuit board are available.
Call the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Table 1.
Performance Summary ( TA = 25oC )
PARAMETER CONDITION VALUE
Minimum Input Voltage 2V
Maximum Input Voltage 45V
Output Voltage Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
Vin=45V, Iout=20mA
1.2V ±3%
1.5V±3%
1.8V±3%
2.0V±3%
2.5V±3%
3.3V±3%
5.0V±3%
Maximum Output Current 20mA
Quiescent Current <3µA
QUICK START PROCEDURE
The DC1388A is easy to set up to evaluate the per-
formance of the LT3008. Refer to Figure 1. for proper
measurement equipment setup and following the
procedures below:
1. Before proceeding to test, insert jumper JP1
into the OFF position, and use VOUT Select
jumper J1 for the desired output voltage 1.2V,
1.8V, 2.0V, 2.5V, 3.3V or 5.0V. If the output
voltage is different from the above values, use
the USER option and install a resistor R8. Se-
lect R8 according to the following equation:
K
V
V
ROUT 6191
6.0
8⋅
−=
.
Assume 1.2V is the desired output for the fol-
lowing evaluations.
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1388A
3µA QUIESCENT CURRENT, 20mA LINEAR REGULATOR
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2. Apply 2V across Vin (to Gnd). Insert jumper
JP1 into the ON position. Draw 20mA of load
current. The measured Vout should be 1.2V ±
3% (1.164V to 1.236V).
3. Vary the input voltage from 2V to 45V and the
load current from no load to 20mA. Vout
should measure 1.2V ± 3% (1.164V to
1.236V).
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1388A
3µA QUIESCENT CURRENT, 20mA LINEAR REGULATOR
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