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dc2543af

DEMO MANUAL DC2543A

Description

LTC7820EUFD

High Efficiency, Charge Pump

DC/DC Converter

Demonstration circuit 2543A is a high efficiency, high

density, open loop charge pump (inductorless) DC/DC

converter. This demo board is a voltage divider which

achieves a 2:1 step-down ratio from an input voltage from

36V to 60V. The output voltage is a fixed ratio of half of the

This demo board has the option to deliver a 20A maximum

load with the addition of 15 chip capacitors. See Figures 8

and 10 for the details.

The DC2543A provides a very high efficiency solution of

in Figure 3. When configured for a 20A output, an effi-

at 20A as shown in Figure 8.

The demo board features the LTC®7820, a fixed ratio high

voltage high power switched capacitor/charge pump

controller in a 4mm × 5mm QFN package. Please see

LTC7820 data sheet for more detailed information.

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog

Devices, Inc. All other trademarks are the property of their respective owners.

performance summary

The DC2543A needs to be powered on with no load cur-

rent or a very small load current (less than 50mA) with the

is established. The board offers a disconnect FET option

which is controlled by the LTC7820 FAULT pin to discon-

nect the load during startup as shown in the schematic.

Please refer to “Voltage Divider Prebalance Before Switch-

ing” section in the LTC7820 data sheet for more details

regarding the startup of the voltage divider. The board also

features some protection functions such as overcurrent

and thermal shutdown to make it a reliable solution.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2543A

PARAMETER

CONDITION

VALUE

Input Voltage Range

36V to 60V

10A

Typical Efficiency

98.7%

Peak Efficiency

99%

Switching Frequency

200kHz