Part No. 02-GAM-06 Rev. 1.0 – 042805

WWW.GALAXYPWR.COM

GAMW1V540 – 3

Galaxy Power Inc.

155 Flanders Road

Westborough, MA 01581

Telephone: 508-870-9775

Fax: 508-870-9796

e-mail: info@galaxypwr.com

Galaxy’s proprietary CoolConverter™ provides:

•Patented single-stage power conversion architecture,

control, and magnetic design allow unprecedented power

density and efficiency in an isolated power supply.

• An advanced microcontroller reduces parts count while

adding features, performance, and flexibility in the design.

•Low common-mode noise as a result of lower capacitance

in the transformer from balanced winding design.

Protection and Control

Valid Input Voltage Range:

The converter measures the input voltage and will

not allow operation outside of the input voltage

specification. As shown by the graphs, hysteresis is

added to both the high and low voltage to prevent

the converter from turning on and off repeatedly

when the voltage is held near either voltage extreme.

At low line this assures the maximum input current is

not exceeded; at high line this assures the semicon-

ductor devices in the converter are not damaged by

excessive voltage stress.

ON/OFF Logic Option:

The ON/OFF control logic can be either Negative

(standard) or Positive to enable the converter. For

Negative logic the ON/OFF pin is brought to below

1.0V with respect to the –INPUT pin to enable the

converter. The pull down must be able to sink

100µA. For Positive logic the ON/OFF pin is brought

to greater than 4.0V with respect to the –INPUT pin

and be limited to less than 10V. To request the

Positive logic version, add the suffix (P) to the stan-

dard part number. The ON/OFF pin has a built-in pull

up resistor of approximately 100kΩ to +5V.

Application Notes

Undervoltage Hysteresis

1.0

0

30

34

37

Input Voltage (V)

36

32

33

35

31

Overvoltage Hysteresis

1.0

0

76.5

78.5

80.5

Input Voltage (V)

79.5

77.5

78

80

79

77