1/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 2010 AX6602 300ma ldo regulato r with enable ? general description the AX6602 is a 300ma, low quiescent, high psrr, low noise and low dropout linear regulator. the device includes pass element, error amplifier, band-gap, current limit and thermal shutdown circuitry. the characteristics of low dropout voltage and less quiescent current make it good for some critical current application, for example, some battery powered devices. the typical quiescent current is approximately 90a . in the shutdown mode, the maximum supply current is less than 1ua. the output voltage is adjustable from 1.225 to 5.5v. built-in current-limit, short current protection and thermal-shutdown functions prevent any fault condition from ic damage. ? features - input voltage range is up to 6 v - 2 00mv d ropout at 15 0ma output current - guaranteed 300ma output current - low quiescent current 90 a (typ.) - adjustable output voltage form 1.225v to 5.5v - maximum shutdown current <1ua - fast transient response - current limit and thermal shutdown protection - short circ uit current fold - back - available in the 5 - pin pb - free sot - 23 package ? b lock d iagram cur rent limit - + vi n vout gnd error amp bandgap t hermal shutdown enabl e en fb v?mw`r?y?b? w w w . g o f o t e c h . c o m
2/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? pin assignment the package of AX6602 is sot - 23- 5l; the pin assignment is given by : name description vin inpu t voltage gnd ground en active - low shutdown input. a logic low reduces the supply current to less than 1 a. connect to v in or floating for normal operation. fb feedback input for setting the output voltage. connect to an external resistor divider for ad justable output operation. vout regulator output voltage. adjustable from 1.225v to +5.5v. ? rder/marking information order information top marking ? absolute maximum ratings (at t a =25 c ) charac teristics symbol rating unit v in pin voltage v in gnd - 0.3 to + 6 .5 v output voltage v out gnd - 0.3 to v in + 0.3 v en pin voltage v e n gnd - 0.3 to + 6.5 v fb pin voltage v fb gnd - 0.3 to + 6.5 v power dissipation pd 400 mw storage temperature range t st - 40 to +150 c operating junction temperature t j - 4 0 to + 125 c thermal resistance from junction to case jc 18 0 c /w thermal resistance from junction to ambient ja 250 c /w note : ja is measured with the pcb copper area of approximately 1 in 2 (multi- layer). ( t o p v i e w ) s o t - 2 3 - 5 l 3 2 5 4 1 v i n g n d e n f b v o u t a x 6 6 0 2 x x b : s o t - 2 3 - 5 l p a c k a g e p a c k i n g b l a n k : b u l k a : t a p i n g l ax 6602 ww : 01 ~ 26 ( a ~ z ) 27 ~ 52 ( a ~ z ) year : a = 2010 1 = 2011 id code : internal 1 y w x v?mw`r?y?b? w w w . g o f o t e c h . c o m
3/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? e lectrical c haracteristics t a =25 c (unless otherwise noted) characteristics symbol conditions min typ max units input voltage v in (note1) 2. 6 - 6 v fb voltage v fb vin=2.6 v to 6v, i out =1ma 1.2 1.225 1.25 v fb input leakage current i fb v fb =1. 225 v - 100 - 100 na adjustable output voltage range v out v fb - 5 .5 v quiescent current i q i out =0ma, v in =5v - 90 - a shutdown current i sd i out =0ma, v en =0v - - 1 a dropout voltage (note 2) v drop i out =300ma v out =1.50v - 1. 1 0 1. 3 v v out =1.80v - 0.8 1. 0 v out =2.50v - 0. 4 0. 6 v out =3.00v - 0. 37 0.5 v out =3.30v - 0.36 0.5 v out =4.75v - 0.25 0.5 cur rent limit (note 3 ) i limit 400 600 - ma short circuit current i short v out <1.0v - 17 0 - ma load regulation (note 4 ) v load i out =10m~300ma - - 0.02 %/ma ripple rejection psrr c in =1f c o ut =2.2uf i out =100ma f=12 0hz - 60 - db f=1khz - 55 - enable inp ut threshold v enh regulator enable 2.0 - - v v enl regulator shutdown - - 0. 8 enable pin current i e n h v en =v in - 0.003 0.1 a i e n l v en =0v - 0.35 1 thermal shutdown t sd - 150 - oc thermal shutdown hysterics t s h - 30 - oc note 1 : minimum v in voltag e is defined by output adds a dropout voltage. note 2 : the dropout voltage is defined as (vin-vout), the performance of every AX6602 part, see typical performance characteristics . note 3 : current limit is measured at constant junction temperature by usin g pulsed testing with a low on time. note 4 : regulation is measured at constant junction temperature by using pulsed testing with a low on time. v?mw`r?y?b? w w w . g o f o t e c h . c o m
4/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? application circuit ? f unction d escriptions a minimum of 2.2f capacitor must be connected from v out to ground to insure stability. typically a large storage capacitor is connected from v in to ground to ensure that the input voltage does not sag below the minimum dropout voltage during the load transient response. this pin must always be dropout voltage higher than v out in order for the device to regulate properly. enable function the AX6602 features an ldo regulator enable/disable function. to assure the ldo regulator will switch on; the en turn on contr ol level must be greater than 2.0 volts. the ldo regulator will go into the shutdown mode when the voltage on the en pin falls below 0. 8 volts. for to protecting the system, the AX6602 have a quick - discharge function. if the enable function is not needed in a specific application , it may be tied to vin to keep the ldo regulator in a continuously on state . fb function the output is an adjustable version, the fb voltage is 1.225v. the output voltage can be set by outside resistances. the output voltage, v out, is then given by the following equation: v out = 1.225 (1 + r1/r2) for the reasons of reducing power dissipation and loop stability, r2 is recommending to choose 50 k~3 00k . en on off vin vout gnd in c v in out c ax 6602 1 uf 2 . 2 uf out v en fb r 1 r 2 v out = v fb *( 1 + r 1 / r 2 ) v fb = 1 . 225 v r 2 range = 50 k ~ 300 k v?mw`r?y?b? w w w . g o f o t e c h . c o m
5/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? a pplication i nformation like any low-dropout regulator, the AX6602 requires input 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. capacitor selection normally, use a 1f capacitor on the input and a 2.2f capacitor on the output of the AX6602. larger input capacitor values and lower esr (x5r, x7r) provide better supply-noise rejection and transient response. a higher- value output capacitor (10f) may be necessary if large, fast transients are anticipated and the device is located several inches from the power source. input-output (dropout) voltage a regulator's minimum input- to -output voltage differential (dropout voltage) determines the lowest usable supply voltage. in battery-powered systems, this determines the useful end- of -life battery voltage. because the device uses a pmos, its dropout voltage is a function of drain-to source on -resistance, r ds (on) , multiplied by the load current: v dropout = v in -v out = r ds (on) x i out current limit an d short-circuit protection the AX6602 uses a current sense-resistor to monitor the output current. a portion of the pmos output transistors current is mirrored to a resistor such that the voltage across this resistor is proportional to the output current. once the output current exceeds limit threshold, AX6602 would be protected with a limited output current. further more, when the output is short to ground, the output current would be folded-back to a less limit. thermal considerations the AX6602 series can deliver a current of up to 300ma over the full operating junction temperature range. however, the maximum output current must be dated at higher ambient temperature to ensure the junction temperature does not exceed 125c. 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 current and the voltage drop across regulator. p d = (v in - v out ) i out v?mw`r?y?b? w w w . g o f o t e c h . c o m
6/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 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 (125c) and t a is the maximum ambient temperature. the junction to ambient thermal resistance ( ja ) for sot23-5 package at recommended minimum footprint is 250c/w. visit our website in whi ch recommended footprints for soldering surface mount packages for detail. pcb layout an input capacitance of ? 1f is required between the AX6602 input pin and ground (the amount of the capacitance may be increased without limit), this capacitor must b e located a distance of not more than 1cm from the input and return to a clean analog ground. input capacitor can filter out the input voltage spike caused by the surge current due to the inductive effect of the package pin and the printed circuit boards routing wire. otherwise, the actual voltage at the in pin may exceed the absolute maximum rating. the output capacitor also must be located a distance of not more than 1cm from output to a clean analog ground. because it can filter out the output spike caused by the surge current due to the inductive effect of the package pin and the printed circuit board s routing wire. v?mw`r?y?b? w w w . g o f o t e c h . c o m
7/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? t ypical c haracteristics ? vcc vs. quiescent current 0 20 40 60 80 100 120 2.5 3.3 4 4.5 5 5.5 6 vcc (v) quiescent current (ua) vcc vs. output voltage 3.27 3.28 3.29 3.3 3.31 3.32 3.33 3.6 4 4.5 5 5.5 6 vcc (v) output voltage (v) output current vs. output voltage 3.25 3.26 3.27 3.28 3.29 3.3 3.31 3.32 3.33 3.34 3.35 0 50 100 150 200 250 300 output current (ma) output voltage (v) output current vs. dropout voltage 0 0.1 0.2 0.3 0.4 0.5 0.6 50 100 150 200 250 300 output current (ma) dropout voltage (v) vout=2.5v vout=3.3v temperature vs. quiescent current vcc=3.6v 0 30 60 90 120 150 180 210 -40 -20 0 25 50 85 105 125 temperature ( : ) quiescent current (ua) temperature vs. shutdown current vcc=3.6v 0 2 4 6 8 10 -40 -20 0 25 50 85 105 125 temperature ( : ) shutdown current (ua) v?mw`r?y?b? w w w . g o f o t e c h . c o m
8/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? typical characteristics ( continuous ) power - on load tran sient temperature vs. output voltage vcc=3.6v 3.1 3.15 3.2 3.25 3.3 3.35 3.4 3.45 3.5 -40 -20 0 25 50 85 105 125 temperature ( : ) output voltage (v) temperature vs. current limit vcc=3.3v 350 400 450 500 550 600 -40 -20 0 25 50 85 105 125 temperature ( : ) current limit (ma) v?mw`r?y?b? w w w . g o f o t e c h . c o m
9/9 axelite confidential materials, do not copy or distribute without written consent. rev. 1. 4 jun.29, 20 10 AX6602 ? p ackage o utlines symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a - - 1.45 - - 0.057 a1 0 0.08 0.15 0 0.003 0.006 a2 0.9 1.1 1.3 0.035 0.043 0.051 b 0.3 0.4 0.5 0.012 0.016 0.02 c 0.08 0.15 0.22 0.003 0.006 0.009 d 2.7 2.9 3.1 0.106 0.114 0.122 e1 1.4 1.6 1.8 0.055 0.063 0.071 e 2.6 2.8 3 0.102 0.11 0.118 l 0.3 0.45 0.6 0.012 0.018 0.024 l1 0.5 0.6 0.7 0.02 0.024 0.028 e1 1.9 bsc 0.075 bsc e 0. 95 bsc 0.037 bsc 0 o 4 o 8 o 0 o 4 o 8 o 1 5 o 10 o 15 o 5 o 10 o 15 o 2 5 o 10 o 15 o 5 o 10 o 15 o jedec outline: mo - 178 aa l e 1 e 1 e d a 2 a 1 b ( 5 x ) a d e t a l a l 1 1 ( 4 x ) 2 ( 4 x ) e g a u g e p l a n e c d e t a l a v?mw`r?y?b? w w w . g o f o t e c h . c o m
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