ame, inc. 1 ame8861 600ma cmos ldo n typical application n functional block diagram l very low dropout voltage l 600ma output l accurate to within 1.5% l 30 m a quiescent current l over-temperature shutdown l current limiting l short circuit current fold-back l noise reduction bypass capacitor l power-saving shutdown mode l space-saving sot-25 package l factory pre-set output voltages l low temperature coefficient the ame8861 family of positive, linear regulators fea- ture low quiescent current (30 m a typ.) with low dropout voltage, making them ideal for battery applications. the space-saving sot-25 package is attractive for "pocket" and "hand held" applications. these rugged devices have both thermal shutdown, and current fold-back to prevent device failure under the "worst" of operating conditions. in applications requiring a low noise, regulated supply, place a 1000 pf capacitor between bypass and ground. the ame8861 is stable with an output capacitance of 2.2 m f or greater. l instrumentation l portable electronics l wireless devices l cordless phones l pc peripherals l battery powered widgets l electronic scales n general description n features n applications amp gnd out in r1 r2 v ref =1.215v byp overcurrent shutdown thermal shutdown en ame8861 output input c3 2.2 m m m m f c1 1 m m m m f gnd out 5v en byp in c2 1000pf
ame, inc. 2 600ma cmos ldo ame8861 part number marking output voltage package operating temp. range ame8861a eev250 axcww 2.5v sot-25 - 40 o c to + 85 o c ame8861a eev300 awgww 3.0v sot-25 - 40 o c to + 85 o c ame8861a eev330 axcww 3.3v sot-25 - 40 o c to + 85 o c n pin configuration ame8861 1. in 2. gnd 3. en 4. byp 5. out sot-25 top view n ordering information please consult ame sales office or authorized rep./distributor for other output voltage and package type availability. 13 2 5 4 ame8861 operating temperature range number of pins package type pin configuration special feature ame8861 x x x x x x voltage a: 1. in e: -40 o c to 85 o c e: sot-2x v: 5 300: v=3.0v l: low profile 2. gnd 250: v=2.5v y: lead free & low profile 3. en 330: v=3.3v z: lead free 4. byp 5. out special feature pin configuration voltage operating temperature range package type number of pins
ame, inc. 3 ame8861 600ma cmos ldo parameter maximum unit input voltage 8 v output current p d / (v in - v o )a input, output voltage gnd - 0.3 to v in + 0.3 v esd classification b parameter rating unit ambient temperature range - 40 to + 85 o c junction temperature - 40 to + 125 o c n absolute maximum ratings n recommended operating conditions n thermal information caution: stress above the listed absolute maximum rating may cause permanent damage to the device maximum unit thermal resistance ( q ja ) sot-25 260 o c / w internal power dissipation (p d ) (dt = 100 o c) sot-25 380 mw 150 o c 300 o c maximum lead temperature (10 sec) parameter maximum junction temperature
ame, inc. 4 600ma cmos ldo ame8861 parameter symbol min typ max units input voltage v in note 1 7 v output voltage accuracy v o -1.5 1.5 % 1.3v<=v o(nom) <=1.4v 1900 1.4v= 4.0v -0.4 0.2 0.4 load regulation reg load 0.2 1 % over temperature shutdown ots 150 o c over temperature hysterisis oth 30 o c v o temperature coefficient tc 30 ppm/ o c f=1khz 75 f=10khz 55 f=100khz 30 v eh 2.0 vin v v el 00.4v i eh 0.1 m a i el 0.5 m a shutdown supply current i sd 0.5 1 m a pg leakage current i lc 1 m a test condition i o =1ma to 600ma i o =1ma v o >1.2v v o >1.2v v o <0.8v i o =0ma dropout voltage v dropout i o =600ma v o =v o(nom) -2.0% see chart mv i o =1ma to 600ma line regulation reg line i o =1ma v in =v o +1 to v o +2 % power supply rejection psrr i o =100ma c o =2.2 m f ceramic c byp =0.01 m f db 30 m vrms output voltage noise en f=10hz to 100khz i o =10ma, c byp =0.01 m f co=2.2 m f en input threshold en input bias current v pg =7v v en =v in , v in =2.7v to 7v v en =0v, v in =2.7v to 7v v in =5v, v o =0v, v en ame, inc. 5 ame8861 600ma cmos ldo the ame8861 family of cmos regulators contain a pmos pass transistor, voltage reference, error amplifier, over-current protection, and thermal shutdown. the p-channel pass transistor receives data from the error amplifier, over-current shutdown, and thermal pro- tection circuits. during normal operation, the error ampli- fier compares the output voltage to a precision reference. over-current and thermal shutdown circuits become ac- tive when the junction temperature exceeds 150 o c, or the current exceeds 600ma. during thermal shutdown, the output voltage remains low. normal operation is re- stored when the junction temperature drops below 120 o c. the ame8861 switches from voltage mode to current mode when the load exceeds the rated output current. this prevents over-stress. the ame8861 also incorpo- rates current foldback to reduce power dissipation when the output is short circuited. this feature becomes ac- tive when the output drops below 0.8 volts, and reduces the current flow by 65%. full current is restored when the voltage exceeds 0.8 volts. n detailed description n external capacitors the ame8861 is stable with an output capacitor to ground of 2.2 m f or greater. ceramic capacitors have the lowest esr, and will offer the best ac performance. con- versely, aluminum electrolytic capacitors exhibit the high- est esr, resulting in the poorest ac response. unfortu- nately, large value ceramic capacitors are comparatively expensive. one option is to parallel a 0.1 m f ceramic capacitor with a 10 m f aluminum electrolytic. the benefit is low esr, high capacitance, and low overall cost. a second capacitor is recommended between the in- put and ground to stabilize vin. the input capacitor should be at least 0.1 m f to have a beneficial effect. a third capacitor can be connected between the by- pass pin and gnd. this capacitor can be a low cost polyester film variety between the value of 0.001 ~ 0.01 m f. a larger capacitor improves the ac ripple rejec- tion, but also makes the output come up slowly. this "soft" turn-on is desirable in some applications to limit turn-on surges. all capacitors should be placed in close proximity to the pins. a "quiet" ground termination is desirable. this can be achieved with a "star" connection. n enable the enable pin normally floats high. when actively, pulled low, the pmos pass transistor shuts off, and all internal circuits are powered down. in this state, the qui- escent current is less than 1 m a. this pin behaves much like an electronic switch.
ame, inc. 6 600ma cmos ldo ame8861 ground current vs. input voltage load step (1ma-600ma) drop out voltage vs. output voltage power supply rejection ratio safe operating area power supply rejection ratio ground current ( m m m m a) input voltage (v) 0 5 10 15 20 25 30 35 40 45 012345678 85 o c 25 o c psrr (db) 100ma 10ma 1ma 100 m a 100ma 100 m a c l =2.2 m f tantalum c byp =0 -80 -70 -60 -50 -40 -30 -20 -10 0 10 1k 100k frequency (hz) 10m -80 -70 -60 -50 -40 -30 -20 10 1k 100k 10m psrr (db) frequency (hz) c l =2.2 m f tantalum c byp =1000pf 100ma 100 m a 1ma 10ma 100ma 100 m a time ( 20ms/div) i l (200ma/div) vo(10mv/div) i load out put c l =2. 2 m f ci n=2. 2 m f 0 270 400 650 1.2 2 3 output current (ma) input-output voltage differential (v) 0 200 400 600 800 1000 1200 12 34 5 6 i load =600ma drop out voltage (v) output voltage (v)
ame, inc. 7 ame8861 600ma cmos ldo short circuit response overtemperature shutdown current limit response noise measurement chip enable transient response line transient response time (20ms/div) vo (1mv div) c l =2.2 m f no filter v out (1v/div) i out (200ma/div) time (0.5sec/div) 0 0 r load =6.6 w i out (200ma/div) v out (1v/div) tim e (2ms/div) c load =2.2 m f c in =1.0 m f r load =3.3 w v outnom =3.3v tim e (2ms/div) c load =2.2 m f c in =1 m f r load <100m w v out (1v/div) i out (200mv/div) v out (10mv/div) v in (1v/div) c load =2.2 m f i load =1ma v outdc =3.3v v indc =4.5v time (200ms/div) 0 0 time ( 1ms/div) c l =2 m f r l =10 w output (1v/div) enable (2v/div)
ame, inc. 8 600ma cmos ldo ame8861 n package dimension sot-25 min max min max a a 1 0.00 0.15 0.0000 0.0059 b 0.30 0.55 0.0118 0.0217 d 2.70 3.10 0.1063 0.1220 e 1.40 1.80 0.0551 0.0709 e h 2.60 3.00 0.10236 0.11811 l 1 0 o 10 o 0 o 10 o s 1 0.37bsc 0.0146bsc 0.95bsc 0.0374bsc 1.90 bsc 0.07480 bsc symbols millimeters inches 1.20ref 0.0472ref l top view side view front view c 1 d s1 e e h a1 b a
life support policy: these products of ame, inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of ame, inc. ame, inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. ? ame, inc. , november 2003 document: 2006-ds8861-d corporate headquarter u.s.a. (subsidiary) ame, inc. analog microelectronics, inc. 2f, 189 kang-chien road, nei-hu district 3100 de la cruz blvd., suite 201 taipei 114, taiwan, r.o.c. santa clara, ca. 95054-2046 tel: 886 2 2627-8687 tel : (408) 988-2388 fax: 886 2 2659-2989 fax : (408) 988-2489 www.ame.com.tw e-mail: sales@ame.com.tw
|
