me 218 8 v2 .0 page 1 of 9 high efficiency ,synchronous pfm step-up dc-dc converter general description features selection guide me 2188 series is a pfm step-up dc/dc converter ic with low supply current by cmos process. high frequency noise that occurs during switching is reduced by using advanced circuit designed, output voltage is programmable in 0.1v steps between 1.8v~5.0v and maximum frequency is 350khz(t yp .). a low ripple, high efficiency step- up dc/dc converter can be constructed of me 2188 xxx with only two external components. me 2188 xxx is suitable for use with battery-powered instruments with low noise and low supply current. typical application ? power source for battery-powered equipment ? power source for wireless mouse,toys, cameras, vcrs, pdas, mp3, and led lighting etc typical application circuit ? high efficiency 95% ? maximum frequency 350 khz ? low quiescent current 15 a ? input voltage: 0.9v~5.0v ? output voltage range:1.8v to 5.0v ? high accuracy: 2% ? low ripple and low noise ? package: sot23-3, sot23-5 v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 2 of 9 pin configuration pin assignment type postfix package switching transistor ce funct ion features me 2188 axx m3 sot23-3 build in transistor no lx me 2188 cxx m5 sot23-5 build in transistor yes lx+ce me 2188 axx pin number pin name description sot23-3 1 gnd g ro und 3 vout voltage output 2 lx switch pin me 2188c xx pin number pin name function sot23-5 1 ce chip enable 2 vout output voltage monitor, ic internal power supply 3 nc nc 4 gnd ground 5 lx switch absolute maximum ratings parameter symbol ratings units supply voltage v max 8 v lx pin current ilxmax 1000 ma continuous total power dissipation sot23 p d 3 00 mw sot89 p d 500 mw to92 p d 500 mw operating temperature range t opr - 2085 storage temperature range t stg -40~125 esd v esd 2000 v n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 3 of 9 block diagram electrical characteristics t a =25 0 c, v in =v out 0.6 v, l= 22 h c in =10 f c out = 100 f , unless otherwise noted . me 2188 axx/cxx symbol parameter test conditions mi n typ max unit v ou t output voltage v out 0.9 8 v out v out 1.02 v v in supply voltage 0.9 - 5 v v start start voltage iload=1ma vin 02v - - 0.95 v vhold hold voltage iload=1ma vin 20v 0.5 - - v f osc oscillation frequency - 3 50 - khz efficiency - 90 95 % ilimit current limit 800 1000 1200 ma i in quiescent current - 15 - a note 1 inductor 22h r<0.5 2 capacitor tantalum type operation description me 2188 step - up dc/dc converter charges energy in the inductor when lx transistor is on, and discharges the energy wi th the addition of the energy from input power source thereto, so that a higher output voltage than the input voltage is obtained. following is the operation diagram. n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 4 of 9 switching dc/dc step up converter operating process ? pcb layout ? set external components as close as possible to the ic and minimize the connection between the components and the ic. in particular, when an external component is connected to vout pin, make minimum connection with the capacitor. ? make vss pin sufficient grounding, otherwise, t he zero level within ic will varied with the switching current. this may result in unstable operation of ic. n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 5 of 9 type characteristics start hold vin=1.2v vin=1.5v vin=1.8v vin=1.2v vin=1.5v vin=1.8v me2188a22 me2188a22 me2188a22 n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 6 of 9 start hold me2188a30 me2188a30 vin=1.5v vin=1.8v vin=2.4v me2188a30 vin=1.5v vin=1.8v vin=2.4v n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 7 of 9 packaging information packaging type: sot23-3 dim millimeters inches min max min max a 2.7 3.1 0.1063 0.122 b 1.7 2.1 0.0669 0.0827 b 0.35 0.5 0.0138 0.0197 c 1.0 1.2 0.0394 0.0472 c 0.1 0.25 0.0039 0.0098 d 0.2 - 0.0079 - e 2.6 3.0 0.1023 0.1181 e 1.5 1.8 0.059 0.0708 n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 8 of 9 packaging type: sot23-5 dim millimeters inches min max min max a 0.9 1.45 0.0354 0.0570 a1 0 0.15 0 0.0059 a2 0.9 1.3 0.0354 0.0511 b 0.2 0.5 0.0078 0.0196 c 0.09 0.26 0.0035 0.0102 d 2.7 3.10 0.1062 0.1220 e 2.2 3.2 0.0866 0.1181 e1 1.30 1.80 0.0511 0.0708 e 0.95ref 0.0374ref e1 1.90ref 0.0748ref l 0.10 0.60 0.0039 0.0236 a 0 0 0 30 0 0 0 30 0 n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
me 218 8 v2 .0 page 9 of 9 ? the information described herein is subject to change without notice. ? na njing micro one electronics inc is not responsible for any problems caused by circuits or diagrams described herein whose related industrial properties, patents, or other rights belong to third parties. the application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. ? use of the information described herein for other purposes and/or reproduction or copying without the express permission of nanjing micro one electronics inc is strictly prohibited. ? the products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of nanjing micro one electronics inc. ? although nanjing micro one electronics inc exerts the greatest possible effort to ensure high quality and reliability, the failure or malfunction of semiconductor products may occur. the user of these products should therefore give thorough consideration to safety design, including redundancy, fire-prevention measures, and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue. n ~n?t?m?w3^v?mw`r?y?b?g ?pqls? tel: 0755-8398 3377 / 135 9011 2223 http://www.gofotech.com v?mw`r?y?b? w w w . g o f o t e c h . c o m
|
