Application Notes
CoolConverter
™
Family
Galaxy’s
C
OOL
C
ONVERTER
™
Family features:
• 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:
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. Shut
down for over-input voltages is inhibited for 100 ms
transients to prevent false shut down due to
transient input voltage conditions.
ON/OFF Logic:
The Leo family of converters comes standard
with both positive and negative logic input-side
shutdown pins and positive logic secondary-side
shutdown. All enable pins have internal pull-ups of
approximately 0.2mA. The secondary-side enable
allows for system sequencing without the need for
an opto-isolator. For the converter to operate all
negative logic enable inputs must be less than one
volt and the positive logic enable must be greater
than 4V or open-circuited.
Leo Series, Page 3
PRELIMINARY
Part No. 99–001 Rev. 4.0–120902
GALAXY [ GALAXY POWER, INC. ]
