National Semiconductor announced the addition of six high-frequency buck regulators to its Simple Switcher product family along with a "dial-in" performance enhancement to its Webench design environment. As national Semiconductor stated, the six regulators feature a combination of high performance, flexibility and ease-of-use for DC-DC power supply designs.
Design results are verified by Webench online electrical and thermal simulations and created for 24-48 hour delivery using the BuildIt! custom prototype power supply kit. The regulators operate with an input voltage range up to 75V and deliver up to 3A of continuous output current. The emulated-current-mode technology provides load transient response in low duty cycle applications that are not addressable by traditional current mode control.
Operating frequency is adjustable from 50 kHz to 1 MHz. To reduce EMI, a frequency synchronization pin allows multiple ICs from the family to self-synchronize or to synchronize to an external clock.
Six products are included in the new line of Simple Switcher regulators. The 0.5A LM5574, 1.5A LM5575 and 3.0A LM5576 buck regulators feature a wide input voltage range from 6V to 75V and adjustable switching frequency between 50 kHz and 500 kHz. The 0.5A LM25574, 1.5A LM25575 and 3.0A LM25576 buck regulators feature input voltage range from 6V to 42V and adjustable switching frequency between 50kHz and 1MHz. Offered in a 16-pin TSSOP, the LM5574 integrates a 75V, 750 milli-Ohm, N-channel MOSFET and the LM25574 integrates a 42V, N-channel MOSFET. Offered in a 20-pin TSSOP package with exposed pad, the LM5576 integrates a 75V, 170 milli-Ohm, N-channel MOSFET and the LM25576 integrates a 42V, N-channel MOSFET.