Application Notes
CoolConverter™
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:
Overvoltage Hysteresis
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.
1.0
0
76.5 77 77.5 78 78.5 79 79.5 80 80.5
Input Voltage (V)
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.
Undervoltage Hysteresis
1.0
0
30
31
32
33
34
35
36
37
Input Voltage (V)
Part No. 02-GAQ-02 Rev. 3.0 – 041405
WWW.GALAXYPWR.COM
GAQW3V330 – 3
Galaxy Power Inc. 155 Flanders Road Westborough, MA 01581 Telephone: 508-870-9775 Fax: 508-870-9796 e-mail: info@galaxypwr.com
GALAXY [ GALAXY POWER, INC. ]
