NATIONAL Semiconductor Corporation, represented in Australia by Arrow Electronics , has expanded its family of high-voltage buck regulators with the introduction of the LM5005.
This high-frequency buck regulator steps down an input voltage from 7V to 75V to produce a regulated 2.5A power supply, adjustable from 1.225V to 65V.
Reliable and compact, the LM5005 is optimised for 48V telecom, automotive and industrial power supply applications.
"The LM5005 addresses our customers' requests for a higher-current version of the popular 75V, 1.0A LM5010 and 75V, 0.5A LM5007 buck regulators," said director of strategic marketing for National Semiconductor's Power Management Group, Paul Greenland.
"The entire family is highly integrated for a smaller overall footprint, with unique, high-frequency PWM control circuitry that allows our customers to implement step-down switching regulators with minimal filtering and external components."
The LM5005 high-voltage switching regulator integrates a 75V N-channel Mosfet and employs a proprietary scheme that uses emulated, current-mode pulse-width modulation (PWM) to produce a 2.5A step-down regulator with minimal external components.
This proprietary control method generates an internal emulated inductor current ramp, which significantly reduces the noise sensitivity of the controller.
This allows the LM5005 to reliably control very small duty cycles so designers can take full advantage of the LM5005's wide 75V input and 500kHz frequency capabilities.
In addition, current-mode control provides inherent line voltage feed-forward and simplified loop compensation.
The programmable operating frequency can range from 50kHz to 500kHz.
A novel, bi-directional oscillator synchronisation pin allows multiple LM5005 regulators to self-synchronise or switch synchronously with an external clock.
Additional protection features include current limit, thermal shutdown and remote shutdown capability.
The device is available in the TSSOP-20 package, featuring an exposed mounting pad to enhance the package's thermal dissipation.