LM2747

www.DataSheet4U.com LM2747 Synchronous Buck Controller with Pre-bias Startup, and Optional Clock Synchronization March 2006 LM2747 Synchronous Buck Controller with Pre-bias Startup, and Optional Clock Synchronization General Description The LM2747 is a high-speed synchronous buck regulator controller with a feedback voltage accuracy of ± 1%. It can provide simple down conversion to output voltages as low as 0.6V. Though the control section of the IC is rated for 3 to 6V, the driver section is designed to accept input supply rails as high as 14V. The use of adaptive non-overlapping MOSFET gate drivers helps avoid potential shoot-through problems while maintaining high efficiency. The IC is designed for the more cost-effective option of driving only N-channel MOSFETs in both the high-side and low-side positions. It senses the low-side switch voltage drop for providing a simple, adjustable current limit. The LM2747 features a fixed-frequency voltage-mode PWM control architecture which is adjustable from 50 kHz to 1 MHz with one external resistor. In addition, the LM2747 also allows the switching frequency to be synchronized to an external clock signal over the range of 250 kHz to 1 MHz. This wide range of switching frequency gives the power supply designer the flexibility to make better tradeoffs between component size, cost and efficiency. Features include the ability to startup with a pre-biased load on the output, soft-start, input undervoltage lockout (UVLO) and Power Goo...