general description the MAX8723 is a high-efficiency, switch-mode, step- down regulator with a 14v internal power switch. with only a few external passive components, this low-cost regulator can generate a fixed 3.3v or adjustable dc output voltage of 2.0v to 3.6v (dual mode) from a 6v to 13.2v dc source. the 13.2v input voltage range makes this part ideal for lcd displays, point-of-load regulators, and other 8/12v- powered industrial equipment applications. the MAX8723 can deliver up to 2a. it features an inter- nal power mosfet, a built-in bootstrap diode for its mosfet driver, and an interface for an external syn- chronous rectifier mosfet drive to replace the schottky diode and improve efficiency. its fixed-fre- quency pwm/skip-mode operation and current-mode control architecture provide fast load-transient response without compensation. the switching fre- quency is a pin-selectable 500khz, 1mhz, or 1.5mhz, minimizing the size of external components. the MAX8723 has built-in soft-start, current-limit, ther- mal-shutdown, and timer-delayed output-fault shutdown functions. the soft-start function limits inrush current during startup, avoiding transients that can trigger the front-end protection circuits and lock up the system. the current limit, thermal-shutdown, and timer-delayed output-fault shutdown functions protect the power sup- ply against fault conditions. the MAX8723 also includes a linear regulator (vl) which provides a fixed 5v output (25ma) to support small exter- nal loads. the reference output is high-precision (2v 1%) and can also supply small external load currents. the MAX8723 is available in the 16-pin 4mm x 4mm tqfn package. applications lcd tvs lcd monitors digital system power supplies point-of-load regulators 8/12v industrial equipment features ? 6v to 13.2v input supply range ? integrated 14v 2a n-channel mosfet switch ? preset 1.5% accurate 3.3v fixed output voltage or 2.0v to 3.6v adjustable output (dual mode) ? current-mode pwm operation ? frequency-selectable 500khz/1mhz/1.5mhz ? internal 5v linear regulator supports up to 25ma external load ? 2v precision reference (1%) ? integrated bootstrap diode for high-side mosfet drive ? external synchronous rectifier driver ? built-in soft-start ? 200a standby mode ? timer-delayed output fault protection ? thermal shutdown protection ? small 16-pin 4mm x 4mm thin qfn package MAX8723 low-cost, internal-switch, step-down regulator for lcd displays ________________________________________________________________ maxim integrated products 1 part temp range pin-package pkg code MAX8723ete+ -40? to +85? 16-pin thin qfn 4mm x 4mm t1644-4 simplified operating circuit ordering information ref bst v cc shdn skip vl gnd fsel c ref c vl ext i.c. ep c bst pgnd out fb in lx c out out in c inl inl c in d l MAX8723 xx-xxxx; rev 0; 3/06 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. pin configuration appears at end of data sheet.
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