May 2005 www.DataSheet4U.com
LM2746 Low Voltage N-Channel MOSFET Synchronous Buck Regulator Controller
LM2746 Low Volt...
May 2005 www.DataSheet4U.com
LM2746 Low
Voltage N-Channel
MOSFET Synchronous Buck Regulator Controller
LM2746 Low
Voltage N-Channel
MOSFET Synchronous Buck Regulator Controller
General Description
The LM2746 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 sections of the IC are rated for 3 to 5.5V, the driver sections are designed to accept input supply rails as high as 16V. The use of 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 fixed-frequency
voltage-mode PWM control architecture is adjustable from 50 kHz to 1 MHz with one external resistor. 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 soft-start, input under
voltage lockout (UVLO) and Power Good (based on both under
voltage and over
voltage detection). In addition, the shutdown pin of the IC can be used for providing startup delay, and the soft-start pin can be used for implementing precise tracking, for the purpose of sequencing with respect to an external rail....