3 to 20 V input, 1 A, high frequency step-down converter with light load efficiency

The LM2734Z regulator is a monolithic, high-frequency, PWM step-down DC–DC converter assembled in a thick 6-pin SOT and a WSON non-pullback package. The device provides all the active functions to provide local DC–DC conversion with fast transient response and accurate regulation in the smallest possible PCB area.

With a minimum of external components and online design support through WEBENCH™, the LM2734Z is easy to use. The ability to drive 1-A loads with an internal 300-mΩ NMOS switch using state-of-the-art 0.5-µm BiCMOS technology results in the best power density available. The world class control circuitry allows for ON-times as low as 13 ns, thus supporting exceptionally high-frequency conversion over the entire 3-V to 20-V input operating range down to the minimum output voltage of 0.8 V. Switching frequency is internally set to 3 MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequency is very high, efficiencies up to 85% are easy to achieve. External shutdown is included, featuring an ultra-low standby current of 30 nA. The LM2734Z uses current-mode control and internal compensation to provide high-performance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, and output overvoltage protection.