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 compared to planar magnetics and
metal baseplate designs.
• Higher reliability than planar transformer designs that can
suffer from via fatigue from thermal cycling, and metal
baseplate designs with board to board interconnects that
are subject to mechanical stress on electrical connections.
Protection and Control
Valid Input Voltage Range:
Overvoltage Lockout
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
75
76
77
78
79
80
Input Voltage (V)
ON/OFF Logic Option:
Undervoltage Lockout
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 below 1.0 V
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 standard part number.
The ON/OFF pin has a built-in pull up resistor of
approximately 100kΩ to +5V.
Voltage
Rising
Voltage
Falling
30
32
34
36
38
40
Input Voltage (V)
Pisces Series, Page 3
Part No. 99-002 Rev. 4.0–093003
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GALAXY [ GALAXY POWER, INC. ]
