ame, inc. 1 ame8890 150ma cmos ldo n typical application n functional block diagram n general description n features n applications the ame8890 is a fixed 1.2v of positive, linear regula- tor feature low quiescent current (60 m a typ.) with low dropout voltage, making them ideal for battery applica- tions. the space-saving sot-23-5 package is attractive for "pocket" and "hand held" applications. this rugged device has both thermal shutdown, and current fold-back to prevent device failure under the "worst" of operating conditions. an additional feature is a "power good" detector, which pulls low when the output is out of regulation. the ame8890 is stable with an output capacitor of 2.2 m f or greater. l very low dropout voltage l guaranteed 150ma output l accurate to within 3% l 60 m a quiescent current l over-temperature shutdown l current limiting l short circuit current fold-back l power good output function l power-saving shutdown mode l space-saving sot-25 (sot-23-5) l low temperature coefficient l instrumentation l portable electronics l wireless devices l cordless phones l pc peripherals l battery powered widgets l electronic scales ame8890 out in c2 2.2 m m m m f c1 1 m m m m f gnd out 5v en pg in gnd out in pg overcurrent shutdown thermal shutdown en amp r2 r1 delay
ame, inc. 2 150ma cmos ldo ame8890 figure 1. typical application schematic v i v o pg gnd en ame8890 1 2 3 4 5 1.2v 2.2uf 47k w w w w optional: en may be connected to v i enable shutdown figure 2. typical application for processor vid code power sequencing schematic v i v o pg gnd en ame8890 1 2 3 4 5 v cc3_3 1uf v cc1_2 10k w w w w 2.2uf
ame, inc. 3 ame8890 150ma cmos ldo pin number pin name pin function 1 in supply input 2 gnd ground 3en enable/shutdown (input) : cmos compatible input. logic high = enable;logic low = shutdown. do not leave open. 4 pg power good output 5 out regulator output n pin configuration ame8890 1. in 2. gnd 3. en 4. pg 5. out n ordering information ww: represents the date code please consult ame sales office or authorized rep./distributor for other package type availability. sot-25 top view 13 2 5 4 ame8890 n pin description part number marking output voltage package operating temp. range ame8890teev atbww 1.2v sot-25 - 40 o c to + 85 o c AME8890TEEVZ atbww 1.2v sot-25 - 40 o c to + 85 o c
ame, inc. 4 150ma cmos ldo ame8890 parameter maximum unit input voltage 7 v output current p d / (v in - v o )ma output voltage gnd - 0.3 to v in + 0.3 v esd classification b n absolute maximum ratings n recommended operating conditions n thermal information parameter rating unit ambient temperature range - 40 to + 85 o c junction temperature - 40 to + 125 o c maximum unit thermal resistance ( q ja ) sot-25 260 o c / w internal power dissipation (p d ) ( d t = 100 o c) sot-25 380 mw 150 o c 300 o c parameter maximum junction temperature maximum lead temperature (10 sec) caution: stress above the listed absolute maximum rating may cause permanent damage to the device
ame, inc. 5 ame8890 150ma cmos ldo n electrical specifications v in = 2.7v, v en = v in , i out =100 m a,ta = 25 o c unless otherwise noted note1:v in(min) =v out +v dropout parameter symbol min typ max units input voltage v in 2.7 6 v output voltage accuracy v o -3 3 % 1.0v ame, inc. 6 150ma cmos ldo ame8890 n detailed description the ame8890 family of cmos regulators contain a pmos pass transistor, voltage reference, error amplifier, over-current protection, thermal shutdown, and power good function. 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 300ma. during thermal shutdown, the output voltage remains low. normal operation is re- stored when the junction temperature drops below 120 o c. the ame8890 switches from voltage mode to current mode when the load exceeds the rated output current. this prevents over-stress. the ame8890 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 0.8volts, and reduces the current flow by 65%. full current is restored when the voltage exceeds 0.8 volts. n external capacitors the ame8890 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. 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. n power good the ame8890 includes the power good feature. when the output is not within 15% of the specified voltage, it pulls low. this can occur under the following conditions: 1) input voltage too low. 2) during over-temperature. 3) during over-current. 4) if output is pulled up. (note: pg pin is an open-drain output.)
ame, inc. 7 ame8890 150ma cmos ldo pg delay time (ms) -45 -5 25 55 85 1.7 1.8 1.9 2.0 2.1 2.2 2.3 temperature ( o c) output voltage vs. temperature quiescent current vs. temperature pg delay time vs. temperature load regulation vs. temperature short circuit current vs. temperature dropout voltage vs. temperature dropout voltage @ 150ma (v) 0.85 0.90 0.95 1.00 1.05 1.10 -45 -5 25 55 85 temperature ( o c) 1.2000 1.2005 1.2010 1.2015 1.2020 1.2025 -45-5 255585 output voltage (v) temperature ( o c) 30 32 34 36 38 40 42 44 -45 -5 25 55 85 quiescent current (ua) temperature ( o c) load regulation 1-150ma (%) -45-5255585 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 temperature ( o c) short circuit current (ma) -45 -5 25 55 85 110 112 114 116 118 120 122 124 temperature ( o c)
ame, inc. 8 150ma cmos ldo ame8890 n timing diagram 95% 95% 95% fault condition 1.5-5ms min-max 1.5-5ms v out v en v pg
ame, inc. 9 ame8890 150ma cmos ldo 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 1.90 bsc 0.07480 bsc symbols millimeters inches 1.20ref 0.0472ref 0.37bsc 0.0146bsc 0.95bsc 0.0374bsc 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. september 2003 document: 2041-ds8890-c corporate headquarter u.s.a. subsidiary ame, inc. analog microelectronics, inc. 2f, 189 kang-chien road, nei-hu dist. 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
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