Buck Regulators Sport Adjustable Frequency Range

The company has added six high-frequency buck regulators to its SIMPLE SWITCHER product family, along with a "dial-in" performance enhancement to its WEBENCH design environment. The 0.5A LM5574, 1.5A LM5575 and 3.0A LM5576 buck regulators feature an input voltage range from 6V to 75V and adjustable switching frequency from 50 kHz to 500 kHz. The 05.A LM25574, 1.5A 25575 and 3.0A LM25576 buck regulators feature an input voltage range from 6V to 42V and adjustable switching frequency from 50 kHz to 1 MHz. The company's patented emulated-current-mode technology enhances load transient response in low duty cycle applications not addressable by traditional current mode control. To reduce EMI, a frequency synchronization pin is used so that multiple ICs from the family can self-synchronize or synchronize to an external clock. Other features are cycle-by-cycle current limit, short-circuit protection and thermal shut down. All six SIMPLE SWITCHER regulators are available now, with prices ranging from $1.35 to $2.90 each/1,000. NATIONAL SEMICONDUCTOR, Santa Clara, CA. (800) 272-9959.