View AX3132_7827120.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 2010 ax 31 3 2 pwm control 2 a step - down converter ? general description AX3132 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. AX3132 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 package, providing such outstanding features as low current consumption. since this converter can accommodate an input voltage up to 3 2 v, it is also suitable for the operation via an ac adapter . ? features - input v oltage 8 v to 32 v - output voltage 3.3v to 26 v - 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 pb - free package. v?mw`r?y?b? www.gofotech.com
2/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? b lock d iagram ? pin assignment the package of AX3132 is sop - 8l- ep ; the pin assignment is given by : name description en/ss on/o ff 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 compensation pin osc frequen cy 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 v?mw`r?y?b? www.gofotech.com
3/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? order/marking information order information top marking ? a bsolute m aximum r atings (at t a =25 c ) characteristics symbol rating unit vcc pi n voltage v cc v ss - 0.3 to v ss + 3 4 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 voltage 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 3 2 v thermal resistance from ju nction to case jc 1 5 c /w thermal resistance from junction to ambient ja 4 0 c /w 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 3 2 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 l o g o y a x 3 p a r t n u m b e r i d c o d e : i n t e r n a l w w : 0 1 ~ 5 2 y e a r : 1 0 = 2 0 1 0 1 1 = 2 0 1 1 1 3 2 y w w x v?mw`r?y?b? www.gofotech.com
4/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? e lectrical c haracteristics ( v cc = 12v, t a =25c, unless o therwise specified) characteristics symbol conditions min typ max units feedback voltage v fb v cc = 10v~ 3 2 v 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 2 . 3 - - a adjustable f requency range f osc 5 0 - 38 0 khz short frequency f osc1 v cc = 10v~ 32 v 45 50 55 khz en /ss pin shutdown l ogic input 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 - 1 30 1 6 0 m efficiency effi v cc = 12v, v out = 5v , i out = 2a - 91 - % v cc = 28 v, v out = 5v , i out = 2a 8 7 v?mw`r?y?b? www.gofotech.com
5/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? a pplication c ircuit el cap el capacitor compensation table cout esr range frequency (hz) v in range r2 c9 c2 l1 30m~80m 50k 8~ 32 v 100 4 n 7 33 00 p 1 0 0u 1 5 0k 560 4 n 7 2 200 p 68u 250k 560 4 n 7 1000 p 33u 3 5 0k 1k 6 n 8 1 0 00 p 22u 80m~300m 50k 100 4 n 7 33 00 p 1 0 0u 1 5 0k 560 4 n 7 1500 p 68u 250k 560 4 n 7 68 0 p 33u 3 5 0k 1k 6 n 8 68 0 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 ~ 3 2 v v o u t = 5 v / 2 a d 1 b 2 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 3 2 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 c 1 0 0 . 1 u f v?mw`r?y?b? www.gofotech.com
6/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? 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 application, the pin m ust 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 threshold voltage. o sc external frequency set pin. the pin connects a resistance (r3) to reduce system frequency. this converter s frequency can be set from 50k to 350khz, please refer the below table to set frequency. t=room temperature r3 ( ) 10m 240 k 110k 68k frequency (hz) 52k 150k 250k 350k 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 setting the output voltage application circuit item shows the basic application circuit with adjustable output version. the external resistor sets the output voltage according 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 ? ? ? ? ? ? ? ? ? r r v v out . v?mw`r?y?b? www.gofotech.com
7/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 inductor selection for most designs, the different frequency can be reducing the inductor value; the AX3132 is suggested 22 h to 100 h for 350k to 50k hz frequencies. please refer the below table to design. l1 recomme nd value ( v in = 8~ 32 v ,v out = 5 v, i out = 2 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 currents. choose inductor ripple current approximately 30% of the maximum load current 2a, 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 (2 a+ 0. 3a ). 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 regulator is approximate ly 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 important paramete r. 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 ? ? ? v?mw`r?y?b? www.gofotech.com
8/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? t ypical c hara cteristics v?mw`r?y?b? www.gofotech.com
9/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? typical characteristics (c ontinuous ) v?mw`r?y?b? www.gofotech.com
10/ 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? typical characteristics (continuous) power - on wave (f=60 khz) (v in =12v, v out =5v, load=2 a, c en/ss =0.1u f) power - on wave (f=60khz) (v in =24v, v out = 5v, load= 2 a, c en/ss =0.1u f) enable - on wave (60khz) (v in =12v, v out =5v, load=2a, c en/ss = 0.1u f) enable - on wave (6 0khz) (v in =24v, v out =5v, load=2 a, c en/ss =0.1u f) load transient (f=60khz) (v in =12v, v out =5v, load=0. 2 ~ 1.8 a) load transient (f=60khz) (v in =24v, v out =5v, load=0. 2 ~ 1.8 a) v?mw`r?y?b? www.gofotech.com
11 / 11 axelite confidential materials, do not copy or distribute without written consent . rev. 1. 0 oct. 20 , 20 10 ax 31 3 2 ? p ackage o utlines 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: ms - 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 v?mw`r?y?b? www.gofotech.com

▲Up To Search▲

Price & Availability of AX3132

	To Download AX3132 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .