View AX3111_7801834.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 pwm control 3 a step - down converter ? general description AX3111 consists of step - down switching regulator with pw m control. these devise include a reference voltage source, oscillation circuit, error amplifier, internal pmos and etc. AX3111 provides low - rip ple power, high efficiency, and excellent transient characteristics. the pwm control circuit is able to the duty ratio linearly form 0 up to 100%. this converter is build out soft start function that prevents overshoot and inrush current at startup. an ove r current protect function and short circuit protect function are built inside, and when ocp or scp happens, the operation frequency will be reduced. t he operating frequency is decided by outside resistance . an external compensation is easily to system sta ble; the low esr output capacitor can be used. with the addition of an internal p - channel power mos, a coil, capacitors, and a diode connected externally, these ics can function as step - down switching regulators. they serve as ideal power supply units for portable devices when coupled with the sop - 8l with exposed pad and t dfn - 10l package s , providing such outstanding features as low current consumption. since this converter can accommodate an input voltage up to 40 v, it is also suitable for the operation via an ac adapter. ? features - input v oltage 8 v to 40 v - output voltage 3.3v to 38v - duty ratio 0% to 100% pwm control - oscillation frequency range is 50k ~ 3 5 0khz by outside resistance setting - enable with soft - start function - current limit , short circuit protect (scp) and thermal shutdown protection - built - in internal sw p - channel mos. - sop - 8l - ep and pdip - 8l pb - free package s . free datasheet http://www.0pdf.com
2 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? b lock d iagram ? pin assignment the package s of AX3111 are sop - 8l - ep and pdip - 8l ; the pin assignment is given by : n ame description en/ss on/off shutdown and soft - start pin vss gnd pin vgate driver gate clamping pin. the pin must connect a 1uf capacitor to vcc vcc ic power supply pin sw switch pin. connect external inductor and diode here. fb feedback pin comp co mpensation pin osc frequency set pin. the pin connect a resistance to gnd. oscillator start - up + thermal shutdown vss sw fb _ comp . v cc current limit + _ amp comp . current source bias 1 . 23 v reference 2 . 5 v regulator comp 0 . 815 v en / ss - pwm switched control circuit vgate osc 5 ua ( t o p v i e w ) 1 2 3 4 8 7 6 5 f b v g a t e s o p 8 l - e p v c c e n / s s o s c v s s s w c o m p s w ( t o p v i e w ) 1 2 3 4 8 7 6 5 p d i p - 8 l a x 3 1 1 1 v g a t e v c c e n / s s v s s f b o s c s w c o m p free datasheet http://www.0pdf.com
3 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? order/marking information order information top marking (sop - 8l - ep /pdip - 8l ) ? a bs olute m aximum r atings (at t a =25 c ) characteristics symbol rating unit vcc pin voltage v cc v ss - 0.3 to v ss + 4 5 v feedback pin voltage v fb v ss - 0.3 to 6 v en/ss pin voltage v en /ss v ss - 0.3 to 6 v osc pin voltage v osc v ss - 0.3 to 3 v comp pin voltag e v comp v ss - 0.3 to 6 v vgate pin voltage v gate v ss - 0.3 to v cc v switch pin voltage v sw v ss - 0.3 to v cc + 0.3 v power dissipation pd internally limited mw storage temperature range t st - 65 to +150 c operating junction temperature range t o j p - 4 0 to +125 c operating supply voltage v op 8 to 40 v thermal resistance from junction to case sop - 8l - ep jc 1 5 c /w pdip - 8l 50 thermal resistance from junction to ambient sop - 8l - ep ja 4 0 c /w pdip - 8l 100 note: ja is measured with the pcb copper area (need connect to exposed pad) of approximately 1.5 in 2 (multi - layer) . p a c k a g e t y p e e s : s o p - 8 l - e p a x 3 1 1 1 x x x p a c k i n g b l a n k : t u b e a : t a p i n g n : p d i p - 8 l logo y ax 3 part number id code : internal ww : 01 ~ 52 year : 10 = 2010 11 = 2011 1 1 1 y w w x free datasheet http://www.0pdf.com
4 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? e lectrical c haract eristics ( v cc = 12v, t a =25c, unless otherwise specified) characteristics symbol conditions min typ max units feedback voltage v fb v cc = 10v~30v i out = 0 to 2a tj= - 20 c ~125 c 0.800 0.8 15 0.830 v quiescent current i ccq v fb =1.2v force driver off - 3 6 ma feedback bias current i fb i out =0.1a - 0.1 0.5 ua shutdown supply current i sd v en/ss =0v - 3 6 m a current limit i cl 3. 5 - - a adjustable f requency range f osc 5 0 - 38 0 khz short frequency f osc1 v cc = 10v~30v 45 5 5 65 khz en /ss pin shutdown l ogic in put threshold voltage v enl - - 0.8 v en /ss pull high current i en/ss v en /ss = 0v - 5 - ua internal mosfet r dson r dson v cc =12v, v fb =0v - 130 18 0 m efficiency effi v cc = 12v, v out = 5v , i out = 2a - 91 - % v cc = 30v, v out = 5v , i out = 2a 8 7 free datasheet http://www.0pdf.com
5 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? a pplication c ircuit (1) el cap el capacitor compensation table cout esr range frequency (hz) vin range r2 c9 c2 l1 30m~80m 50k 8~40v 470 4 n 7 2700 p 1 0 0u 1 5 0k 470 4 n 7 1200 p 68u 250k 470 4 n 7 1000 p 33u 3 5 0k 47 0 4 n 7 1200 p 22u 80m~300m 50k 470 4 n 7 2700 p 1 0 0u 1 5 0k 470 4 n 7 1500 p 68u 250k 470 4 n 7 560 p 33u 3 5 0k 470 4 n 7 270 p 22u c 5 4 7 0 u f c 4 4 7 0 u f 1 2 l 1 r 1 5 . 6 k r 4 1 . 1 k v i n + 8 ~ 4 0 v v o u t = 5 v / 3 a d 1 b 3 4 0 c 3 0 . 1 u f o s c e n / s s v g a t e v c c g n d c o m p f b s w a x 3 1 1 1 e s r 1 r 4 v f b = 0 . 8 1 5 v ; r 4 s u g g e s t 0 . 8 k ~ 3 k v o u t = v f b x ( 1 + ) c 7 0 . 1 u f c 6 0 . 1 u f r 3 c 1 1 u f c 9 r 2 c 2 r 5 c 1 0 0 . 1 u f 1 8 k ( o p t i o n ) free datasheet http://www.0pdf.com
6 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 (2) tantalum chip cap tantalum capacitor compensation table frequency (hz) vin rang e r 2 c9 c2 l1 50k 8~40v 750 1n 2700p 1 0 0u h 1 5 0k 470 4n7 1000p 6 6 u h 300 k 470 10n 560p 33u h c 5 4 7 0 u f c 4 1 0 0 u / 1 6 v 1 2 l 1 r 1 5 . 6 k r 4 1 . 1 k v i n + 8 ~ 4 0 v v o u t = 5 v / 3 a d 1 b 3 4 0 c 3 0 . 1 u f o s c e n / s s v g a t e v c c g n d c o m p f b s w a x 3 1 1 1 e s r 1 r 4 v f b = 0 . 8 1 5 v ; r 4 s u g g e s t 0 . 8 k ~ 3 k v o u t = v f b x ( 1 + ) c 7 0 . 1 u f c 6 0 . 1 u f r 3 c 1 1 u f c 9 r 2 c 2 r 5 c 1 0 0 . 1 u f 1 8 k ( o p t i o n ) free datasheet http://www.0pdf.com
7 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? f unction d escriptions en/ss this pin can be supplied shutdown or soft start function. i t is inside pull high function. f or normal applic ation, the pin must be connected a capacitor to ground. there is a 5ua current to charge this capacitor, vary the different capacitor value to control soft start time. a llow the switching regulator circuit to be shutdown pulling this pin below a 0.8v thres hold voltage. osc external frequency set pin. the pin connects a resistance (r3) to reduce system frequency. this converter s frequency can be set from 50k to 35 0khz, please refer the below table to set frequency. t=room temperature r3 ( comp compensation pin. for el output capacitor application, t he comp pin connects r2 and c 9 to ground for all condition; please refer the compensation table. ? application information set ting the output voltage a pplication circuit item shows the basic application circuit with adjustable output version. the external resistor sets the output voltage accor ding to the following equation: table 1 resistor select for output voltage setting v out r 4 r1 5 v 1.1 k 5.6 k 3.3 v 2.7 k 8.2 k ? ? ? ? ? ? ? ? ? 4 1 1 815 0 r r v v out . free datasheet http://www.0pdf.com
8 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 inductor selection for most designs, the different frequency can be reducing the inductor value; the AX3111 is suggested 22 h to 100 h for 35 0k to 50k hz frequencies . please refer the below table to de sign. l1 recommend value ( v in = 8~ 40 v ,v out = 5 v, i out = 3 a) frequency (hz) 50k 150 k 25 0k 3 5 0k l1 value (h) 1 0 0 uh 68u h 33u h 22u h where is inductor ripple current. large value inductors lower ripple current and small value inductors result in high ripple cur rents. choose inductor ripple current approximately 20 % of the maximum load current 3 a, i l = 0.6 a. the dc current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation ( 3 a+ 0. 3 a ). input capacitor selection this capacitor should be located close to the ic using short leads and the voltage rating should be approximately 1.5 times the maximum input voltage . the rms current rating requirement for the input capacitor of a buck regulat or is approximately 1?2 the dc load current. a low esr input capacitor sized for maximum rms current must be used. a 470 f low esr capacitor for most applications is sufficient. output capacitor selection the output capacitor is required to filter the output and provide regulator loop stability. t he important capacitor parameters are; the 100 khz equivalent series resistance (esr), the rms ripples current rating, voltage rating, and capacitance value. for the output capacitor, the esr value is the most importa nt parameter. the esr can be calculated from the following formula. = 0. 6 a x 8 0m= 48 mv an aluminum electrolytic capacitor's esr value is related to the capacitance and its voltage rating. in most case, higher voltage electrolytic capacitors have lower esr values. most of the time, capacitors with much higher voltage ratings may be needed to provide the low esr values required for low output ripple voltage. it is recommended to replace this low esr capacitor by using a 470 f low esr values < 8 0m . esr i v l ripple ? ? ? free datasheet http://www.0pdf.com
9 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? t ypical c hara cteristics 0 1 2 3 4 5 6 8 12 16 20 24 28 32 36 40 vin vs quiescent current vin (v) quiescent current (ma) vfb=1.2v 0.8 0.805 0.81 0.815 0.82 0.825 0.83 8 12 16 20 24 28 32 36 40 vin vs feedback voltage vin (v) feedback voltage (v) f=300khz iout=300ma 0.8 0.805 0.81 0.815 0.82 0.825 0.83 0 0.5 1 1.5 2 2.5 3 iout vs feedback voltage iout (a) feedback voltage (v) vin=12v 0.8 0.805 0.81 0.815 0.82 0.825 0.83 -40 -20 0 25 50 85 105 125 temperature vs feedback voltage temperature feedback voltage (v) vin=36v iout=0.2a 0 1 2 3 4 5 6 -40 -20 0 25 50 85 105 125 temperature vs quiescent current temperature quiescent current (ma) vin=36v vfb=1.2v 0 50 100 150 200 250 300 350 400 -40 -25 0 25 50 85 105 125 temperature vs frequency temperature frequency (hz) vin=12v iout=0.3a free datasheet http://www.0pdf.com
10 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? typical characteristics (c ontinuous ) 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 0.5 1 1.5 2 2.5 3 efficiency test (60khz) iout (a) efficiency vin=30v vin=20v vin=10v vout=5v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 0.5 1 1.5 2 2.5 3 efficiency test (150khz) iout (a) efficiency vin=30v vin=20v vin=10v vout=5v 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 0.5 1 1.5 2 2.5 3 efficiency test (330khz) iout (a) efficiency vin=30v vin=20v vin=10v vout=5v free datasheet http://www.0pdf.com
11 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? typical characteristics (continuous) power - on wave (f=60 khz) (vin=12v, vout=5v, load=2 a, c en/ss =0.1u f) power - on wave (f=60khz) (vin=24v, vout= 5v, load= 2 a, c en/ss =0.1u f) enable - on wave (60khz) (vin=12v, vout=5v, load=2a, c en/ss = 0.1u f) enable - on wave (6 0khz) (vin=24v, vout=5v, load=2 a, c en/ss =0.1u f) load transient (f=60khz) (vin=12v, vout=5v, load=0.3~2.7a) load transient (f=60khz) (vin=24v, vout=5v, load=0.3~2.7a) free datasheet http://www.0pdf.com
12 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 ? p ackage o utlines (1) sop - 8l - ep symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a - - 1.75 - - 0.069 a1 0 - 0.15 0 - 0.06 a2 1.25 - - 0.049 - - c 0.1 0.2 0.25 0.0075 0.008 0.01 d 4.7 4.9 5.1 0.185 0.193 0.2 e 3.7 3.9 4.1 0.146 0.154 0.161 h 5 .8 6 6.2 0.228 0.236 0.244 l 0.4 - 1.27 0.015 - 0.05 b 0.31 0.41 0.51 0.012 0.016 0.02 e 1.27 bsc 0.050 bsc y - - 0.1 - - 0.004 x - 2.34 - - 0.092 - y - 2.34 - - 0.092 - 0 o - 8 o 0 o - 8 o mold flash shall not exceed 0.25mm per side jedec outline: m s - 012 ba detail a l h e a a 2 a 1 e d 7 ( 4 x ) b y c detail a y x expose pad free datasheet http://www.0pdf.com
13 / 13 axelite confidential materials, do not copy or distribute without written consent . rev. 2. 1 nov . 14 , 20 1 1 ax 31 1 1 (2) pdip - 8l symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a - - 5.33 - - 0.210 a1 0.38 0.015 - - a2 2.92 3.30 4.95 0.115 0.130 0.195 b 0.36 0.46 0.51 0.014 0.018 0.02 0 b1 1.14 1.52 1.78 0.045 0.060 0.070 b2 0.76 0.99 1.14 0.030 0.039 0.045 c 0.20 0.25 0.36 0.008 0.010 0.014 d 9.02 9.27 10.16 0.355 0.365 0.400 e 7.62 7.87 8.26 0.300 0.310 0.325 e1 6.10 6.35 7.11 0.240 0.250 0.280 e 2.54 bsc 0.100 bsc l 2.92 3.00 3.81 0.115 0.130 0.150 eb - - 10.92 - - 0.430 s 0.13 - - 0.005 - - jedec outline: mo - 100 ba e 1 d 7 ( 4 x ) a l a 2 a 1 b 2 b 1 b e s 15 ( 4 x ) e c eb e - pin o 0 . 118 inch pin # 1 indent o 0 . 025 free datasheet http://www.0pdf.com

▲Up To Search▲

Price & Availability of AX3111

	To Download AX3111 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .