Quick Start Procedure - Linear Technology DC2003A Demo Manual

DEMO MANUAL DC2003A

Quick start proceDure

Demonstration circuit 2003A is easy to set up to evaluate
the performance of the LTC3622. Please refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
1. Place jumpers in the following positions:
Table 1. Jumper Selection
JP1 JP2
RUN1 RUN2
ON ON
2. Place VO1 SELECT jumper in 3.3V position (JP9) and
VO2 SELECT jumper in 5V position (JP14).
3. With power off, connect the input power supply at V
and GND.
4. Connect the Loads between V
GND. Preset the loads to 0A.
5. Connect the DMMs to the input and output to monitor
the input voltage and output voltages.
6. Turn on the power supply at the input. The RUN1 and
RUN2 pin jumpers should be at ON position. Measure
and make sure the input supply voltage is 12V. The
output voltage V
should be 5V±1%.
7. Once the input and output voltages are properly es-
tablished adjust the loads within the operating range (0A
to 1A max) and observe the output voltage regulations,
output ripple voltages, switch node wave-forms and
other parameters. Refer to Figure 2 for proper input/
output voltage ripple measurement.
2
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JP3 JP4
MODE/SYNC PHASE
BURST 180°
and GND, V
OUT1
should be 3.3V±1%, and V
OUT1
8. To select other output voltages, use the on board user
selectable output voltage jumpers. Shutting down
LTC3622 by placing RUN1 and RUN2 pin jumpers to
the OFF position or turn off the input power supply.
Refer to the following tables (Table 2 and Table 3) for
the output voltage selections and repeat step 3 to 6:
Table 2. V
OUT1
JP5
JP6
ILIM
1.2V
1A
Table 3. V
OUT2
JP11 JP12
1.5V 1.8V
*Note: If JP10 or JP15 is selected, R5 or R15 needs to be calculated
IN1
and inserted to obtain the desired output voltage.
and
OUT2
Note 1: To measure the input/output voltage ripple prop-
erly, do not use the long ground lead on the oscilloscope
probe. See Figure 2 for the proper scope probe technique.
Short, stiff leads need to be soldered to the (+) and (–)
terminals of an output capacitor. The probe's ground ring
needs to touch the (–) lead and the probe tip needs to
touch the (+) lead.
Note 2: DC2003A can also be used to evaluate
OUT2
LTC3622EDE-2 (2.25MHz) by simply changing U1 to
LTC3622EDE-2, L1 to 1µH (Coilcraft XFL4020-102ME)
and L2 to 2.2µH (Coilcraft XFL4020-222ME).
Jumper Selection
JP7 JP8 JP9
1.8V 2.5V 3.3V
Jumper Selection
JP13 JP14
3.3V 5V
JP10
*USER SELECT
JP15
*USER SELECT
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