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dc2052af
DEMO MANUAL DC2052A
QUICK START PROCEDURE
Connecting a PC to DC2052A
You can use a PC to reconfigure the power management
features of the LTC3880 and the LTC3883 such as: nomi-
nal V
OUT
, margin set points, OV/UV limits, temperature
fault limits, sequencing parameters, the fault log, fault
responses, GPIO and other functionality. The DC1613A
dongle may be plugged in regardless of whether or not
VIN is present. Dongle can be hot plugged.
Combining DC2052A with Other Digital Power Demo
Boards
The DC2052A may be plugged together in a multiboard
array with other LTC power system management boards
using J6 and J8.
Measuring Efficiency (See Figure 4)
To accurately measure efficiency of any configuration, do
the following:
• Set JP1, JP2, JP3 to OFF position to disable all the
auxiliary circuits.
• Make sure R53, R54 are not stuffed.
• Measure
V
IN
across the input ceramic capacitor (C28).
Measure V
OUT
across the output ceramic capacitor
(C32).
Evaluating the DC2052A When V
IN
is Below 6.0V
For applications that the input voltage is within 4.5V to
6.0V, please install R5 to connect VIN directly to INTVCC.
Please be aware that in this case VIN cannot exceed 6.0V
otherwise the chip will be damaged.
Evaluating the LTC3880-1 and LTC3883-1
For applications that require the highest possible efficiency,
the LTC3880-1 and LTC3883-1 allow the user to supply
the bias voltage and gate driver current from an external
power supply. Connect the external power supply, 4.8V
to 5.2V, to the EXTVCC pin.
To use the onboard LDO to drive INTVCC, make the fol-
lowing modifications to the demo board:
• Set JP1 to ON so that U4 provides the 5V drive to
INTVCC. U4 takes the place of the external power supply.
• Install R53, R54.
To accurately measure efficiency of a demo board contain-
ing the LTC3880-1 and the LTC3883-1,
• Drive INTVCC from an external source through the pin
named: EXTVCC.
• Set JP1 to OFF to disable the LDO.
• Measure
V
IN
across the input ceramic capacitor (C28).
Measure V
OUT
across the output ceramic capacitor
(C32).
Measuring Output Ripple Voltage
An accurate ripple measurement may be performed by
using the below configuration across C16.
Figure 4. Typical Efficiency Curves DC2052A, 12V
IN
,
F
SW
= 350kHz, V
OUT
= 1.0V,1.2V,1.5V
