LM3743 Datasheet | National Semiconductor

Description The LM3743 is a voltage mode PWM buck controller which implements synchronous rectification. It provides a low cost, fault tolerant, and efficient point of load solution. To reduce ponent count several parameters are fixed, such as switching frequency and the short circuit protection level. For example the LM3743 has an operating switching frequency of 300 k Hz or 1 MHz and a fixed 500 m V high side current limit for switch node short-circuit protection. LM3743 is a very fault tolerant IC with switch node short-circuit, output undervoltage protection, and the ability to self recover after the removal of the fault. It avoids the need to over design ponents due to thermal runaway during a fault condition, thus resulting in a lower cost solution. It employs a proprietary monotonic glitch free pre-bias start-up method suited for FPGAs and ASIC logic devices. A 0.8V internal reference with ± 1.75% accuracy is ideal for sub-volt conversion. An external programmable soft-start allows for tracking and timing flexibility. The driver features 1.6Ω of pull-up resistance and 1Ω of pull-down drive resistance for high power density and very efficient power processing. n Reference accuracy: ± 1.75%, over full temperature and input voltage range n Low-side sensing programmable current limit n Fixed high-side sensing for supplemental short-circuit protection n Undervoltage protection n Hiccup mode protection eliminates thermal runaway during fault conditions n Externally programmable soft-start with tracking capability n Switching frequency options of 1 MHz or 300 k Hz n Pre-bias start-up capability n MSOP-10 package Applications n n n n n n n ASIC/FPGA/DSP core power Broadband munications Multi-media Set Top Boxes Networking Equipment Printers/Scanners Servers Low Voltage Distributed Power Features n Input voltage from 3.0V to 5.5V n Output voltage adjustable down to 0.8V Typical Application © 2006 National Semiconductor Corporation DS201774 .national. Dat...