unisonic technologies co., ltd lr9273 preliminary cmos ic www.unisonic.com.tw 1 of 9 copyright ? 2013 unisonic technologies co., ltd qw-r502-a30.a super low on resistance/low voltage 1a ldo regulator ? description the utc lr9273 is a typical ldo (linear regulator) with features of super low dropout, 1a output current capability, and -3mv typical load regulation at 1a. during operation of the utc lr9273 , the dropout voltage is very low and the response of line transient and load transient are very well. internally, there?re many functions of utc lr9273 which can be seen in the block figure. there are a voltage reference unit, an error amplifier, resistor-net for voltage setting, a current limit circuit, and a chip enable circuit in each utc lr9273 . the utc lr9273 can be used as an ideal of the power supply for hand-held communication equipment, such as: power source for portable communication equipment, power source for electrical appliances, for example, cameras, vcrs and camcorders and power source for battery-powered equipment. ? features * ultra supply current: 60a (typ.) * standby mode: 0.1a (typ.) * very low dropout voltage: 0.18v (typ.) @i out =1a, v out =2.85v * ripple rejection: 70db (typ.) @f=1khz,v out =2.85v * temperature-drift coefficient of output voltage: 100ppm/c (typ.) * well line regulation: 0.02%/ v (typ.) * output voltage accuracy: 1.5% (typ.) * internal fold back protection circuit: 250ma (typ.) @ short mode * c in =c out =4.7f or more (ceramic capacitors) are recommended to be used with this ic sop-8 1 sot-89-5
lr9273 preliminary cmos ic unisonic technologies co., ltd 2 of 9 www.unisonic.com.tw qw-r502-a30.a ? ordering information ordering number package packing lead free halogen free lr9273xl-xx-s08-t lr9273 xg-xx-s08-t sop-8 tube lr9273xl-xx-s08-r lr9273xg -xx-s08-r sop-8 tape reel lr9273xl-xx-ab5-r lr9273xg-xx-ab5-r sot-89-5 tape reel notes: 1. x: the auto discharge function at off state are options as follows. 2. xx: output voltage, refe r to marking information. ? marking information package voltage code marking sot-89-5 28 :2.8v 35 :3.5v ad: adj 123 xx lr9273 date code voltage code 4 5 l: lead free g: halogen free active code sop-8
lr9273 preliminary cmos ic unisonic technologies co., ltd 3 of 9 www.unisonic.com.tw qw-r502-a30.a ? pin configuration ? pin description sot-89-5 pin no. pin name description 1 adj adjust pin (for adjustable version) nc no connection (for fixed version) 2 gnd ground pin 3 ce chip enable pin. active when this pin is high. 4 v in input pin 5 v out output pin hsop-8j pin no. pin name description 1 v out output pin 2 on/off on/off pin 3, 5, 6, 7 nc no connection (note) 4 vss gnd pin 8 v in input pin note: the nc pin is electrically open. the nc pin can be connected to v in or v ss .
lr9273 preliminary cmos ic unisonic technologies co., ltd 4 of 9 www.unisonic.com.tw qw-r502-a30.a ? block diagram for fixed version for adjustable version
lr9273 preliminary cmos ic unisonic technologies co., ltd 5 of 9 www.unisonic.com.tw qw-r502-a30.a ? absolute maximum rating parameter symbol ratings unit input voltage v in 6.5 v input voltage (ce pin) v ce -0.3~6.5 v output voltage v out -0.3~ v in +0.3 v power dissipation p d 900 mw operating temperature t opt -40~+85 storage temperature t stg -55~+125 note: absolute maximum ratings are those values be yond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? electrical characteristics lr9273b/d-xx (fixed output voltage type) parameter symbol test conditions min typ max unit input voltage v in 1.4 6.0 v supply current i ss v in ? v out =1.0v, v ce =v in , i out =0a 60 100 a standby current istandby v in =6.0v, v ce =0v 0.1 1.0 a output voltage v out v in ? v out =1.0v, i out =100ma v out >1.5v 0.98 1.02 v v out 1.5v -30 +30 mv load regulation out out ? i ? v v in ? v out =0.3v, 1ma i out 300ma, if v out 1.1v, then v in =1.4v -15 -2 15 mv v in ? v out =0.3v, 1ma i out 1a, if v out 1.1v, then v in =1.7v -3 mv dropout voltage (t opt =25c) v dif i out =300ma 0.8 v out <0.9 0.33 0.57 v 0.9 v out <1.0 0.22 0.47 v 1.0 v out <1.5 0.18 0.32 v 1.5 v out <2.6 0.10 0.15 v 2.6 v ou 0.05 0.10 v i out =1a 0.8 v out <0.9 0.72 v 0.9 v out <1.0 0.64 v 1.0 v out <1.5 0.56 v 1.5 v out <2.6 0.32 v 2.6 v ou 0.18 v line regulation in out ? v ? v i out =100ma, v out +0.5v vin 6.0v, if v out 0.9v, 1.4v vin 6.0v 0.05 0.20 %/v ripple rejection rr f=1khz (v out 4.0v) 70 db f=1khz (v out >4.0v) ripple 0.5vp-p,vi n ? v out =1.0v, i out =100ma, if v out 1.2v, v in ? v out =1.5v, i out =100ma 60 db output voltage temperature coefficient opt out ? t ? v i out =100ma, -40 t opt 85 100 ppm/ output current i lim v in -v out =1.0v 1 a short current limit i sc v out =0v 250 ma pull-down resistance for ce pin r pd 1.9 5.0 15.0 m ? ce input voltage high v ceh 1.0 6.0 v low v cel 0 0.4 v thermal shutdown detector threshold temperature t tsd junction temperature 150 thermal shutdown released temperature t tsr junction temperature 120 output noise en bw=10hz~100khz 30 vrms
lr9273 preliminary cmos ic unisonic technologies co., ltd 6 of 9 www.unisonic.com.tw qw-r502-a30.a ? electrical characteristics lr9273b/d-xx (adjustable output voltage type) parameter symbol test conditions min typ max unit input voltage v in 1.4 6.0 v supply current i ss v out =v adj , v in =2.0, v ce =v in 60 100 a standby current istandby v in =6.0v, v ce =0v 0.1 1.0 a reference voltage for a djustable voltage regulato r v out v out =v adj , v in =2.0v, i out =100ma 0.970 1.000 1.030 v output voltage range rv out 1.0 v in v load regulation out out ? i ? v v in =1.4v, 1ma i out 300ma -15 -2 15 mv v in =1.7v, 1ma i out 1a -3 mv dropout voltage v dif v out =v adj i out =300ma 0.18 0.32 v i out =1a 0.56 v line regulation in out ? v ? v v out =v adj , i out =100ma, 1.5v v in 6.0v 0.05 0.20 %/v ripple rejection rr f=1khz ripple 0.5vp-p, v out =v adj , v in =2.5v, i out =100ma 70 db output voltage temperature coefficient opt out ? t ? v i out =100ma, -40 t opt 85 100 ppm/ output current i lim v out =v adj , v in =2.0 1 a short current limit i sc v out =v adj =0v 250 ma pull-down resistance for ce pin r pd 1.9 5.0 15.0 m ? ce input voltage high v ceh 1.0 6.0 v low v cel 0 0.4 v thermal shutdown detector threshold temperature t tsd junction temperature 150 thermal shutdown released temperature t tsr junction temperature 120 output noise en bw=10hz~100khz 30 vrms
lr9273 preliminary cmos ic unisonic technologies co., ltd 7 of 9 www.unisonic.com.tw qw-r502-a30.a ? test circuit c1 4.7f v in v out gnd ce utc lr9273 c2 4.7f v out v i out basic test circuit test circuit for supply current c1 4.7f v in v out gnd ce utc lr9273 a c2 4.7f i ss
lr9273 preliminary cmos ic unisonic technologies co., ltd 8 of 9 www.unisonic.com.tw qw-r502-a30.a ? typical application circuit example of the typical application of utc lr9273 (fixed output type) phase compensation in these ics, phase compensation is ma de with the output capacitor for securi ng stable operation even if the load current is varied. for this purpose, use as much as a capacitor as c2. recommendation value is as follows: mounting on pcb make v dd and gnd lines sufficient. if their impedance is high, a current flows, the noise picked up or unstable operation may result. further use a 4.7 f or more value capacitor between v dd pin and gnd pin as close as possible. set an output capacitor between v out pin and gnd pin for phase compensation as close as possible. technical notes on output voltage setting of adjustable output type v out adj gnd i2 i3 1.0v r3 i ic r ic r2 v out
lr9273 preliminary cmos ic unisonic technologies co., ltd 9 of 9 www.unisonic.com.tw qw-r502-a30.a ? typical application circuit(cont.) the output voltage may be adjustable for any out put voltage between its 1.0v reference and its v dd setting level. an external pair of resistors is required, as shown above. the complete equation for the output voltage is described step by step as follows; i2=i ic +i3 ???? (1) i3=1.0/r3 ???? (2) thus, i2=i ic +1.0/r3 ???? (3) therefore, v out =1.0+r2i2 ???? (4) put equation (3) into equation (4), then v out =1.0+r2(i ic +1.0/r3) =1.0(1+r2/r3)+r2i ic ???? (5) in 2nd term, or r2iic will produce an error in vout. in equation (5), i ic =1.0/ ric ???? (6) r2i ic =r21.0/r ic =1.0r2/r ic ???? (7) for better accuracy, choosing r2(< |
