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1/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6644 /5 dual channel ldo regulato r s with enable ? general description the ax6644/5 is a high accurately, low noise, high ripple rejection ratio, low dropout, dual cmos ldo voltage regulators with enable function. the en function allows the output of each regulator to be turned off independently, resulting in greatly reduced power consumption. the ax6644/5 has the soft start function to suppress the inrush current. the current limit is over 25 0ma per channel and also operates as a short protection for the output current limiter. the output voltage for each regulator is set independently by internal setting. the ax6644/5 is fully compatible with low esr ceramic capacitors, reducing cost and improving output stability. this high level output stability is maintained even during frequent load fluctuations, due to the excellent transient response performance and high psrr achieved across a broad range of frequency. it is available in the tsot-23-6l and tdfn - 6l packages . ? features - input voltage range :2. 5 v to 6 v - varied f ixed o utput voltage combinations - 200 mv dropout at 2 00m a output current (v out R 2.5 v) - o utput current : 20 0ma/channel (typ.) - low quiescent current : 60 a (typ.) - current limit and short current protections - t hermal shutdown protection - fast transient response - low esr capacitor compatible (x7r, x5r) - available in the 6 - pin pb - free t sot - 23 and tdfn - 6l p ackage s v?mw`r?y?b? www.gofotech.com
2/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? b lock d iagram ? pin assignment the package s of ax6644/5 are t sot - 23- 6 l and tdfn - 6l; the pin assignment is given by : name description vin power input gnd ground en 1 v out 1 enable control pin en 2 v out 2 enable control pin vout1 output1 voltage vout 2 outpu t2 voltage current limit 1 - + vin vout 1 gnd error amp bandgap thermal shutdown enable 1 en 1 current limit 2 - + error amp enable 2 en 2 vout 2 ( t o p v i e w ) t s o t - 2 3 - 6 l 3 2 6 4 1 v i n g n d e n 1 v o u t 1 5 e n 2 v o u t 2 a x 6 6 4 4 ( t o p v i e w ) t s o t - 2 3 - 6 l 3 2 6 4 1 g n d v i n e n 1 v o u t 1 5 e n 2 v o u t 2 a x 6 6 4 5 tdfn - 6 l ( 2 * 2 ) vout 2 en 1 en 2 1 2 3 4 5 6 vin gnd vout 1 ( top view ) gnd ax 6644 tdfn - 6 l ( 2 * 2 ) vout 2 en 1 en 2 1 2 3 4 5 6 vin gnd vout 1 ( top view ) gnd ax 6645 v?mw`r?y?b? www.gofotech.com
3/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? order/marking information order information top marking ( t sot - 23 - 6l ) top marking ( tdfn - 6l ) appendix part number identification code part number identification code ax6644a pa AX6645a pa ax6644b pb AX6645b pb ax6644c pc AX6645c pd a x66 4 4d pd AX6645d pe ax6644e pe AX6645e pf ax6644f pf AX6645f pg ax6644g pg AX6645g ph ax6644h ph AX6645h pj ax6644j pj AX6645j pm ax6644k pk AX6645k pn ax6644l pl AX6645l pq ax6644m pm AX6645m pr ax6644n p7 AX6645n p8 ax6644p pp AX6645p ps ax6644q pq AX6645q pt ax6644r pr AX6645r pu ax6644 y ps AX6645 y pw ax6644 t pt AX6645 t p y ax6644 v pv AX6645 v p z ax6644w px AX6645w po ax6644x p1 AX6645x p2 a x 6 6 4 4 x x x x c t : t s o t - 2 3 - 6 l o u t p u t t y p e p a c k a g e p a c k i n g a : t a p i n g ( r e f e r t a b l e ) z 6 : t d f n - 6 l ( 2 * 2 ) b l a n k : b a g a x 6 6 4 5 x x x x c t : t s o t - 2 3 - 6 l o u t p u t t y p e p a c k a g e p a c k i n g a : t a p i n g ( r e f e r t a b l e ) z 6 : t d f n - 6 l ( 2 * 2 ) b l a n k : b a g o u t p u t t y p e c o d e : ( v o u t 1 + v o u t 2 ) f : 2 . 8 v + 1 . 2 v g : 2 . 8 v + 1 . 8 v h : 2 . 8 v + 3 . 0 v j : 2 . 8 v + 3 . 3 v k : 3 . 0 v + 3 . 0 v a : 1 . 5 v + 2 . 8 v b : 1 . 8 v + 2 . 8 v c : 1 . 8 v + 2 . 6 v d : 1 . 8 v + 3 . 3 v e : 2 . 5 v + 2 . 8 v l : 3 . 0 v + 3 . 3 v m : 3 . 3 v + 3 . 3 v p : 1 . 8 v + 3 . 0 v q : 1 . 5 v + 2 . 5 v r : 3 . 3 v + 1 . 8 v y : 2 . 8 v + 1 . 5 v t : 1 . 5 v + 3 . 3 v v : 1 . 5 v + 3 . 0 v w : 1 . 2 v + 2 . 8 v x : 1 . 2 v + 1 . 2 v n : 1 . 2 v + 3 . 3 v l i d e n t i f i c a t i o n c o d e w e e k : 0 1 ~ 2 6 ( a ~ z ) 2 7 ~ 5 2 ( a ~ z ) y e a r : a = 2 0 1 0 1 = 2 0 1 1 i d c o d e : i n t e r n a l l y w x x x y w x identification code year : 9 = 2009 a = 2010 week : 01 ~ 26 ( a ~ z ) 27 ~ 52 ( a ~ z ) id code : internal v?mw`r?y?b? www.gofotech.com
4/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? a bsolute m aximum r atings (at t a =25 c ) characteristics symbol rating unit v in pin voltage v in gnd - 0.3 to + 6.5 v output current i out1 / i out2 8 00 ma output voltage v out 1 /v out2 gnd - 0.3 to v in + 0.3 v enable voltage en1/en2 gnd - 0.3 to v in + 0.3 v power dissipation pd 250 mw storage temperature range t st - 40 to +150 c operating temperature range t op - 4 0 to +85 c junction temperature t j - 4 0 to +125 c thermal resist ance from junction to case t sot - 23 - 6l jc 180 c/w tdfn - 6l 25 thermal resistanc e from junction to ambient t sot - 23 - 6l ja 250 c/w tdfn - 6l 120 note: ja is measured with the pcb copper area of approximately 1 in 2 (multi - layer). that need connect to gnd pin or exposed pad ( tdfn - 6l) ? elect rical characteristics ( v in =5v, t a = 25c , unless otherwise noted ) characteristics symbol conditions min typ max units input voltage v in i out =10ma 2. 5 - 6 v output voltage a ccuracy v out i out = 1ma, v in = 5v, v out > 1.8 v - 2 - +2 % i out = 1ma, v in = 5v, v out Q 1.8 v - 0.04 - 0.04 v quiescent current ( c hannel 1+ channel2 ) i cc i out 1 ,2 = 0 ma, v in = 5v - 6 0 100 a dropout voltage v drop i out =200ma, v out = v out - 2% v out =1. 2 v - 1100 1500 mv v out =1.5 v - 800 1200 v out =1 .8 v - 5 00 900 v out R 2.5 v - 2 00 400 current limit (note 1 ) i limit v in = v out + 1.0v, v en = v in 25 0 - - ma short circuit current i short output voltage<0.25*v out , each channel - 150 - ma line regulation v line i out = 1ma, v in = v out +1 v to 6.0v - 0.2 0. 3 % /v v?mw`r?y?b? www.gofotech.com
5/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? elect rical characteristics (continuous) load regulation (note 2 ) v load i ou t = 1~ 1 00ma, v in = v out +1v - 0. 0 1 0.03 % /ma ripple rejection psrr f = 1 20 hz, ,i out = 30 ma - 6 0 - db output voltage temperature coefficient i out = 1 ma (note 3 ) - 100 - ppm/ c enable input threshold v enh 2.0 - - v v enl - - 0. 6 enable pull - high cur rent ( each channel ) i en 1,2 v en1,2 = 0v - 1 2 a shutdown current i sd i out 1,2 = 0ma, v in = 5v, v en 1,2 = 0v - 2 4 a thermal shutdown temperature t s t - 150 - c thermal shutdown hysterisis t s h - 4 0 - c note 1: current limit is measured at constant junction temperature by using pulsed testing wit h a low on time. note 2: regulation is measured at constant junction temperature by using pulsed testing with a low on time. note 3: guaranteed by design. ? a pplication c ircuit ? f unction d escriptions the ax6644/5 is a highly accurate, dual, low noise, cmos ldo voltage regulators with enable function. the output voltage for each regulator is set independently by fuse trimming. as illustrated in function block diagram, it consists of a reference, error amplifier, a p-channel pass transistor, an on/off control logic and an internal feedback voltage divider. the band gap reference is connected to the error amplifier, which compares the reference with the feedback voltage and amplifies the voltage difference. if the feedback voltage is lower than the reference voltage, the pass- transistor gate is pulled lower, which allows more current to pass to the v out pin and increases the output voltage. if the feedback voltage is too high, the pass transistor gate is pulled up to decrease the output voltage. the output voltage is feed back through an internal resistive divider connected to v out pin. additional blocks include an output current limiter, thermal sensor, and shutdown logic. c in 2 . 2 uf vout 2 vout 1 gnd out 2 c v out 2 out 1 c ax 6644 / 5 2 . 2 uf 2 . 2 uf out 1 v en 1 en 2 v in v in v?mw`r?y?b? www.gofotech.com
6/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 enable function en1 and en2 pin start and stop the corresponding outputs independently. when the en pin is switched to the power off level, the operation of all internal circuit stops, the build-in p-channel mosfet output transistor between pins v in and v out is switched off, allowing current consumption to be drastically reduced. dropout voltage a regulators minimum input -output voltage differential, or dropout voltage, determines the lowest usable supply voltage. the ax6644/5 use a p- channel mosfet pass transistor, its dropout voltage is function of drain-to-source on-resistance r ds (on) multiplied by the load current. current limit each channel of ax6644/5 includes a fold back current limiter. it monitors and controls the pass transistors gate voltage, estimates the output current, and limits the output current within 25 0ma. thermal shutdown protection thermal shutdown protection limits total power dissipation of ax6644/5 . when the junction temperature exceeds t j = +150c, a thermal sensor turns off the pass transistor, al lowing the ic to cool down. the thermal sensor turns the pass transistor on again after the junction temperature cools down by 40c, resulting in a pulsed output during continuous thermal shutdown conditions. thermal shutdown protection is designed to protect the ax6644/5 in the event of fault conditions. for continuous operation, the absolute maximum operating junction temperature rating of t j = +125c should not be exceeded. ? a pplication i nformation like any low-dropout regulator, the ax6644/5 requires i nput and output decoupling capacitors. the device is specifically designed for portable applications requiring minimum board space and smallest components. these capacitors must be correctly selected for good performance (see capacitor characteristics section). please note that linear regulators with a low dropout voltage have high internal loop gains which require care in guarding against oscillation caused by insufficient decoupling capacitance. v dropout = v in - v out = r ds ( on ) * i out v?mw`r?y?b? www.gofotech.com
7/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 input capacitor an input capacitance of 2.2 f is required between input pin and ground directly (the amount of the capacitance may be increased without limit). the input capacitor must be located less than 1cm from the device to assure input stability. a lower esr capacitor allows the use of less capacitance, while higher esr type (like aluminum electrolytic) requires more capacitance. capacitor types (aluminum, ceramic and tantalum) can be mixed in parallel, but the total equivalent input capacitance/ esr must be defined as above to stable operation. there are no requirements for the esr on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will be 1 f over the entire operating temperature range. output capacitor the ax6644/5 is designed specifically to work with very small ceramic output capacitors. a ceramic capacitor (temperature characteristics x7r, x5r) in 1 f is suitable for the ax6644/5 application. the recommended capacitance for the device is 2.2 f, x5r or x7r dielectric ceramic, between v out and gnd for stability, but it may be increased without limit. higher capacitance values help to improve transient. the output capacitor's esr is critical because it forms a zero to provide phase lead which is required for loop stability. thermal considerations the ax6644/5 series can deliver a current of up to 20 0ma/channel over the full operating junction temperature range. however, the maximum output current must be debated at higher ambient temperature to ensure the junction temperature does not exceed 125 c. with all possible conditions, the junction temperature must be within the range specified under operating conditions. power dissipation can be calculated based on the output curr ent and the voltage drop across regulator. p d = (v in - v out ) i out + v in i gnd the final operating junction temperature for any set of conditions can be estimated by the following thermal equation: p d (max) = (t j (max) - t a ) / ja where t j (max) is the maximum junction temperature of the die (125 c ) and t a is the maximum ambient temperature. the junction to ambient thermal resistance ( ja ) for tsot- 23 -6l package is recommended 250c/w. v?mw`r?y?b? www.gofotech.com
8/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? typical characteristics v in vs. i ccq 0 20 40 60 80 100 2.5 3 3.5 4 4.5 5 5.5 6 v in (v) i ccq (ua) channel1+channel2 i out1 =i out2 =0ma v in vs. shutdown current 0 1 2 3 4 5 2.5 3 3.5 4 4.5 5 5.5 6 v in (v) shutdown current (ua) v en1 =v en2 =0v v in vs. en threshold 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.5 3 3.5 4 4.5 5 5.5 6 v in (v) en (v) v enh v enl v in vs. v out 1.18 1.184 1.188 1.192 1.196 1.2 1.204 1.208 1.212 1.216 1.22 2.5 3 3.5 4 4.5 5 5.5 6 v in (v) v out (v) i out =1ma v in vs.v out 3.2 3.22 3.24 3.26 3.28 3.3 3.32 3.34 3.36 3.38 3.4 4 4.5 5 5.5 6 v in (v) v out (v) i out =1ma i out vs. v out 1.1 1.12 1.14 1.16 1.18 1.2 1.22 1.24 1.26 1.28 1.3 0 50 100 150 200 i out (ma) v out (v) v in =5v v?mw`r?y?b? www.gofotech.com
9/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? typical characteristics (continuous) i out vs. v out 3.2 3.25 3.3 3.35 3.4 0 50 100 150 200 i out (ma) v out (v) v in =5v i out vs. dropout voltage 0 200 400 600 800 1000 1200 50 100 150 200 i out (ma) dropout voltqge (mv) v out =1.2v v out =1.8v v out =2.8v v out =3.3v temperature vs. i ccq 0 20 40 60 80 100 -40 temperature vs. en threshold 0 0.5 1 1.5 2 -40 temperature vs. v out 1.16 1.18 1.2 1.22 1.24 1.26 -40 temperature vs. v out 3.2 3.25 3.3 3.35 3.4 -40 v?mw`r?y?b? www.gofotech.com
10/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? typical characteristics (continuous) psrr psrr power on power on en on (en1) en on (en2) psrr -80 -70 -60 -50 -40 -30 -20 -10 0 0.1 1 10 100 frequency (khz) psrr (db) v out =1.2v, i out =30ma psrr -80 -70 -60 -50 -40 -30 -20 -10 0 0.1 1 10 100 frequency (khz) psrr (db) v out =3.3v, i out =30ma v?mw`r?y?b? www.gofotech.com
11/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? typical characteristics (continuous) load transient load transient v?mw`r?y?b? www.gofotech.com
12/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 ? p ackage o utlines (1) t sot - 23- 6l symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a - - 1.10 - - 0.043 a1 0.00 - 0.10 0 - 0.004 a2 0.70 0.90 1.00 0.028 0.035 0.039 b 0.30 0.40 0.50 0.0 12 0.016 0.020 c 0.08 0.14 0.20 0.003 0.006 0.008 d 2.80 2.90 3.00 0.110 0.114 0.118 e 2.60 2.80 3.00 0.102 0.110 0.118 e1 1.50 1.60 1.70 0.059 0.063 0.067 e 0.95 bsc. 0.037 bsc. e1 1.90 bsc. 0.075 bsc. l 0.30 0.45 0.60 0.012 0.018 0.024 l1 0.60 re f. 0.024 ref. l2 0.25 bsc. 0.010 bsc. y - - 0.10 - - 0.004 r 0.10 - - 0.004 - - 0 o - 8 o 0 o - 8 o jedec outline: mo-193 aa e 1 e e e 1 b d a a 1 a 2 y l 1 r l c l 2 v?mw`r?y?b? www.gofotech.com
13/ 13 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 5 jun. 28 , 20 11 ax6 6 4 4 /5 (2) tdfn - 6l ( 2*2 0.75mm ) symbol dimensions i n millimeters dimensions i n inches min. nom. max. min. nom. max. a 0.70 0.75 0.80 0.028 0.030 0.031 a1 0.00 0.02 0.05 0.000 0.001 0.00 2 a3 0.203 ref. 0.008 ref . b 0.2 0 0.2 8 0.3 5 0.009 0.011 0.013 d 1.95 2.00 2.05 0.077 0.079 0.081 d2 1. 35 1.5 0 1.6 5 0.055 0.059 0.063 e 1.95 2.00 2.05 0.07 7 0.079 0.081 e2 0. 75 0.9 0 1.0 5 0.031 0.035 0.039 e 0.65 bsc. 0.026 bsc. l 0.20 0.3 0 0.4 0 0.00 8 0.012 0.016 e d a a 1 a 3 d 2 e e 2 ( top view ) ( bottom view ) b pin 1 l seating plane ( side view ) v?mw`r?y?b? www.gofotech.com

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