HR700

The HR40 Series™ DC/DC converters offer the high efficiencies associated with switching regulators, yet have full isolation of input and output grounds. The units are built using thick-film hybrid technology and are sealed in metal packages for high-reliability applications. All models are guaranteed to pass a gross leak test (maximum leak rate of 1 x 10^-3 atm-cc/sec).

The HR40 Series devices are flyback energy storage switching regulators which require a minimum of components resulting in small package size. Single and dual models self-oscillate at an operating frequency which is an approximate inverse function of the load. At full load, the frequency is typically 80 kHz for single and dual output models. Triple output models operate at a fixed frequency of approximately 200 kHz. A transformer in the forward power circuit and an opto-coupler in the feedback/control loop maintain input to output isolation.

The HR40 Series Models are available with single 5 volt, dual 12 or 15 volt, or triple (+5 and either ±12 or ±15) outputs with an input voltage range of 16 to 32 VDC. Output power of up to 4 watts is available from the dual output models for either balanced or unbalanced loads; however, at least 25% of the total load should be on the positive output. The single output device can provide 3.5 watts, and the triple output can supply up to 3.2 watts. The high efficiency is almost constant over the entire input voltage range and from approximately 25% of full load to full load. This makes the unit ideal for battery applications.

An open collector TTL inhibit of HR40 Series is provided to allow power shutdown and startup from a logic input. An open circuit on the inhibit terminal (pin 15) gives normal operation, and a TTL low level shuts down the converter. The inhibit pin has an open circuit voltage of 12 to 28 V. Input current in the shutdown mode will be less than 15 mA. Current limiting is provided on each output for indefinite short circuit protection. Due to the high efficiency, heat sinking requirements are minimized, but consideration should be given to removing self-generated heat when operating these devices at maximum ratings. To increase dissipation, heat conducting material (PCB, copper sheet, heat sink,etc.) should be brought into contact with the converter's baseplate.

The converter HR40 Series can be operated at full load at a case temperature of 85°C, with the output power derated linearly to zero at 105°C.