esmt/emp EML3023 elite semiconductor memory technology inc./elite micropower inc. publication date : apr. 2011 revision : 1.1 1/13 1.5mhz 1a, synchronous step-down regulator general description EML3023 is a high efficiency step down dc/dc converter. it features an extremely low quiescent current, which is suitable for reducing standby power consumption, especially for portable applications. the device can accept input voltage from 2.5v to 5.5v and deliver up to 1a output current. high 1.5mhz switching frequency allows the use of small surface mount inductors and capacitors to reduce overall pcb board space. furthermore, the built-in synchronous switch improves efficiency and eliminates external schottky diode. EML3023 uses different modulation algorithms for various loading conditions: (1) pulse width modulation (pwm) for low output voltage ripple and fixed frequency noise, (2) pulse frequency modulation (pfm) for improving light load efficiency, and (3) low dropout (ldo) mode for providing 100% duty cycle operation during heavy loading. adopting low reference voltage design reduces regulated output to 0.6v. the adjustable version of this device is available in both of tdfn-6 2x2mm and sot-23-5 package. features ? achieve 97% efficiency ? input voltage : 2.5v to 5.5v ? output current up to 1a ? reference voltage: 0.6v ? quiescent current 15 a with no load ? internal switching frequency: 1.5mhz ? no schottky diode needed ? low dropout operation: 100% duty cycle ? shutdown current < 1 a ? excellent line and load transient response ? over-temperature protection applications ? blue-tooth devices ? cellular and smart phones ? personal multi-media player (pmp) ? wireless networking ? digital still cameras ? portable applications typical application fig. 1
esmt/emp EML3023 elite semiconductor memory technology inc./elite micropower inc. publication date : apr. 2011 revision : 1.1 2/13 package configuration sot-23-5 EML3023-00vf05nrr 00 adjustable vf05 sot-23-5 package nrr rohs & halogen free package commercial grade temperature rating: -40 to 85c package in tape & reel order, mark & packing information package vout(v) product id marking packing sot-23-5 adjustable EML3023-00vf05nrr tape & reel 3k units pin functions pin name sot-23-5 function run 1 enable pin. minimum 1.2v to enable the device. maximum 0.4v to shut down the device. vin 4 power input pin. must be closely decoupled to gnd pin with a 4.7 f or greater ceramic capacitor. sw 3 switch pin. must be connected to inductor. this pin connects to the drains of the internal main and sync hronous power mosfet switches. gnd 2 ground pin. vfb (adjustable) 5 feedback pin. receives the feedback voltage from an external resistive divider across the output.
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