2

dc1964afa

DEMO MANUAL DC1964A

Quick start proceDure

Demonstration circuit 1964A is easy to set up to evaluate

the performance of the LTC3110 bidirectional regulator.

RefertoFigure1forpropermeasurementequipmentsetup

and follow the procedure below. 5V power supply should

be rated minimum 2A of output current.

NOTE: When measuring the input or output voltage ripple,

care must be taken to avoid a long ground lead on the

oscilloscope probe. Measure the input or output voltage

probe technique.

To verify the capability of DC1964A for charging superca-

pacitors, proceed with the following steps:

1. Place jumper MODE (JP4) to FIXED FREQ. position.

2. PlacejumperFBCAP(JP5)to5.0Vposition.Placejumper

PROG (JP3) to 0.5A position. Place switch DIR (SW1)

to AUTO position for automatic switch between charge

or backup modes of operation.

3. Place jumper FB (JP1) into 3.2V to set 3.2V voltage on

the load, when supercapacitor C3 discharges in backup

mode.

4. With power off, connect the input power supply to

VEXT, GND load to VSYS, GND as shown on Figure 1.

5. Turn the input power source on and slowly increase the

input voltage to 4.0V. Set the load to 0.2A. You have to

see voltage around 3.6V (diode forward voltage drop

lower compared to VEXT) on the VSYS terminal.

6. Place jumper RUN (JP2) in the ON position. Voltage on

VCAP terminal should rise above 4.8V. If there is no

output, temporarily disconnect the load to make sure

that the load is not set too high.

To verify the ability of DC1964 to work in backup mode,

proceed with the following:

7. Disconnect input power from VEXT (E2) terminal, be-

cause SW1 in AUTO position, supercapacitor C3 starts

discharging, however LTC3110 will maintain a voltage

of 3.3V on terminal VSYS (E2).

8. Repeat steps 1 to 7 for different charging currents and

VSYSvoltages.Whiledischarging,increaseloadcurrent

to 2.0A to verify high current capability and good load

regulation of LTC3110 controller.

9. Youcanmeasurevoltageregulationandrippleinbackup

mode on VSYS (E2) terminals.

10.Make sure that input voltage on VEXT and VSYS ter-

minals does not exceed 5.5V.

Figure 1. Proper Measurement Equipment Setup