Description
The TD Series of DC-to-DC converters feature the highest power density delivering up to 150 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 TD offers thermal shutdown — over-temperature and over-voltage protection that so far, have been available typically in modules twice the size.
When applied correctly, the Model TD 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 TD Series converters from any damage if the output is overloaded or shorted. The TD 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 TD 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 TD 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 TD 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 TD series converters offer users one of the highest reliability DC-to-DC converters in the industry.