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
Undervoltage Lockout
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 semiconductor devices in
the converter are not damaged by excessive voltage
stress.
Voltage
Rising
Voltage
Falling
30
32
34
36
38
40
Input Voltage (V)
ON/OFF Logic Option:
Overvoltage Lockout
The ON/OFF control logic can be either Negative
(standard) or Positive to enable the converter. For
Negative logic, bring the ON/OFF pin to less than 1.0V
with respect to the –INPUT pin to enable the converter.
The pull-down must be able to sink 100µA. For
Positive logic, bring the ON/OFF pin 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 standard part number. The ON/OFF
pin has a built-in pull up resistor of approximately
100kΩ to +5V.
Voltage
Rising
Voltage
Falling
75
76
77
78
79
80
Input Voltage (V)
Pisces II Series, Page 3
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0–061004
GALAXY [ GALAXY POWER, INC. ]
