
Description
The PD301 Series of DC-to-DC converters feature the
highest power density, delivering up to 300 watts of power on the
half-size industry standard footprint and all that in a package which is only 0.50
inch high. In addition, the Model PD301 offers thermal shutdown, over-temperature
and over-voltage protection.
The Model
PD301 allows paralleling of up to 20 modules and Switching Frequency
Synchronization (SYNC) with either another converter or an external clock. This dynamic
and accurate power sharing within an array of parallel modules is accomplished without
the need for external components, trimming, booster module or module matching.
These features, plus high efficiency and the excellent performance of the PD301, have been
made possible by the use of unique (patented) control circuit and integrated magnetics
technology.
When applied correctly, the Model PD301 is virtually
indestructible. If an abnormal and/or potentially destructive condition occurs,
the protection circuits Current Limit, Over-Voltage Protection (OVP), and Thermal
Shutdown cause the Logic Control to "turn-off" the MOSFET, thus turning
off the DC-to-DC converter. The converter can also be turned off externally by applying a
Logic Low signal to "SD" pin.
Over-Current Protection: Two independent output current detection circuits
protect the PD301 series converters from any damage if the output is overloaded or
shorted. The PD301 module uses straight-line current limiting at module temperatures below
80°C and automatically switches to foldback current limiting above 80°C. The output
voltage remains constant and within its specified limits up to the current limit set
point. If the current at rated voltage is greater than the current limit set point, the
output voltage will decrease in order to limit the output current. The module will
automatically resume normal operation after the overload or short-circuit condition is
removed.
Over-Voltage Protection: This is an important feature that protects the
user's circuit when output voltage increases to an undesirable level. The output of the
PD301 module is continuously monitored and fed back to the control circuit (through an
isolation transformer). The module shuts itself down if the output rises above 125% of the
rated voltage. In order to turn the module on, the input power must be turned off and
reapplied.
Over-Temperature Protection (Thermal
Shutdown): When the
temperature of the module reaches 115°C, the PD301 module shuts down. A negative
temperature coefficient thermistor is used as a sensor. The thermistor essentially reduces
the current limit trip point, thereby turning the module off when the junction temperature
of the thermistor reaches 130°C, which corresponds to the base plate temperature of
115°C. The module automatically restarts once the temperature is reduced.
High Reliability Components: The PD301 design utilizes the latest technology for the power ferrite
material for the transformer, aluminum PC board for efficiently removing the heat from the
power components, and ceramic capacitors for input and output filtering. No aluminum
electrolytic capacitors are used in the design. The power MOSFETs and output rectifiers
are selected based only on their superior performance. Together with simple design and
superior components, the Powercube PD301 Series converters offer users one of the highest
reliability DC-to-DC converters in the industry.
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