datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 1 features n wide 8v to 36v input voltage range n output adjustable from 1.25v to 32v n maximum duty cycle 100% n minimum drop out 0.3v n fixed 180khz switching frequency n maximum 3.5a switching current n internal optimize power mosfet n high e fficiency n excellent line and load regulation n with output constant current loop n built in thermal shutdown function n built in current limit function n built in output short protection function n sop8-ep package applications n car charger n battery charger n lcd monitor and lcd tv n portable instrument power supply n telecom / networking equipment general description the XL2010 is a 180 khz fixed frequency pwm buck (step-down) dc/dc converter, capable of driving a 3.5a load with high efficiency, low ripple and excellent line and load regulation. requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator. the pwm control circuit is able to adjust the duty ratio linearly from 0 to 100%. an over current protection function is built inside. when short protection function happens, the operation frequency will be reduced from 180khz to 48khz. an internal compensation block is built in to minimize external component count. figure1. package type of XL2010
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 2 pin configurations figure2. pin configuration of XL2010 (top view) table 1 pin description pin number pin name description 1 nc no connected. 2 sw power switch output pin (sw). sw is the switch node that supplies power to the output. (note: connected the back exposed pad to sw .) 3 gnd ground pin. care must be taken in layout. this pin should be placed outside of the schottky diode to output capacitor ground path to prevent switching current spikes from inducing voltage noise into XL2010. 4 fb feedback pin (fb). through an external resistor divider network, fb senses the output voltage and regulates it. the feedback threshold voltage is 1.25v. 5 en enable pin. drive en pin low to turn off the device, drive it high to turn it on. 6 ocset output constant current set pin. 7 vc internal voltage regulator bypass capacity. in typical system application, the vc pin connect a 1uf capacity to vin. 8 vin supply voltage input pin. XL2010 operates from a 8v to 36v dc voltage. bypass vin to gnd with a suitably large capacitor to eliminate noise on the input. the exposed pad is sw
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 3 function block figure3. function block diagram of XL2010 typical application circuit figure4. XL2010 typical application circuit (vin=8v~36v, vout=5v/3.1a)
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 4 ordering information part number marking id lead free lead free packing type package temperature range XL2010e1 XL2010e1 2500 units on tape & reel xlsemi pb-free products, as designated with e1 suffix in the par number, are rohs compliant. absolute maximum ratings note1 parameter symbol value unit input voltage vin -0.3 to 40 v feedback pin voltage v fb -0.3 to vin v output switch pin voltage v output -0.3 to vin v power dissipation p d internally limited mw thermal resistance (sop8-ep) (junction to ambient, no heatsink, free air) r ja 60 o c/w operating junction temperature t j -40 to 125 o c storage temperature t stg -65 to 150 o c lead temperature (soldering, 10 sec) t lead 260 o c esd (hbm) >2000 v note1: stresses greater than those listed under maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability.
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 5 XL2010 electrical characteristics t a = 25 ;unless otherwise specified. symbol parameter test condition min. typ. max. unit system parameters test circuit figure4 vfb feedback voltage vin = 8v to 36v, vout=5v iload=0.5a to 3.5a 1.225 1.25 1.275 v efficiency ? vin=12v ,vout=5v iout=3.1a - 87 - % electrical characteristics (dc parameters) vin = 12v, gnd=0v, vin & gnd parallel connect a 100uf/50v capacitor; iout=500ma, t a = 25 ; the others floating unless otherwise specified. parameters symbol test condition min. typ. max. unit input operation voltage vin 8 36 v quiescent supply current i q v fb =vin 2.1 5 ma oscillator frequency fosc 144 180 216 khz output short frequency fosp 48 khz switch current limit i l v fb =0 5 a en pin threshold v en high (regulator on) low (regulator off) 1.7 1.1 v max. duty cycle d max v fb =0v 100 % output power pmos rdson v fb =0v, vin=12v, i sw =3.5a 60 80 mohm
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 6 typical system application (vout=5v/3.1a) figure5. XL2010 system parameters test circuit (vin=8v~36v, vout=5v/3.1a) 0.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.03.23.43.6 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 output voltage vs output current output voltage(v) output current(a) vin=12v,vout=5v,rcs=19k vin=24v,vout=5v,rcs=19k figure6. XL2010 system output constant current curve
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 7 0.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.03.23.4 40 45 50 55 60 65 70 75 80 85 90 95 100 efficiency vs load current efficiency(%) load current(a) vin=8v,vout=5v vin=12v,vout=5v vin=24v,vout=5v vin=36v,vout=5v figure7. XL2010 system efficiency curve 0 2 4 6 8 10 12 14 16 18 20 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 output current vs rcs output current(a) rcs(kohm) vin=12v,vout=5v vin=24v,vout=5v iout=1.0a,rcs=5k iout=2.1a,rcs=11k iout=3.1a,rcs=19k figure8. rcs vs output current select curve
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 8 schottky diode selection table current surface mount through hole vr (the same as system maximum input voltage) 20v 30v 40v 50v 60v 1a 1n5817 1n5818 1n5819 1n5820 1n5821 1n5822 mbr320 mbr330 mbr340 mbr350 mbr360 sk32 sk33 sk34 sk35 sk36 30wq03 30wq04 30wq05 31dq03 31dq04 31dq05 3a sr302 sr303 sr304 sr305 sr306 1n5823 1n5824 1n5825 sr502 sr503 sr504 sr505 sr506 sb520 sb530 sb540 sb550 sb560 sk52 sk53 sk54 sk55 sk56 5a 50wq03 50wq04 50wq05
datasheet 3.5a 180khz 36v buck dc to dc converter with cv/cc loop XL2010 rev 1.1 www.xlsemi.com 9 package information package information (sop8-ep)
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